Because, honestly, look what I’m working with. Remember Sartharion, the encounter with no lead-up, no follow-up, no explanation, no nothing? That was an epic saga of love, hate, betrayal, heroism, and ribaldry likely to leave you writhing in a fit of alternating tears and orgasms, compared to ToC.

What the fuck is right. Join me on a quick tour of raid tiers, and their significance, in the past.
Tier 1: Molten Core. The climax of the story of the Dark Iron Dwarves, in which we finally confront the evil force behind their twisted empire on its home turf: the fiery center of Azeroth’s largest (only? never you mind) volcano, infested with the denizens of the infernal realm of molten flame attempting to awaken their evil master, the Firelord Ragnaros. If Ragnaros is not stopped now, all of Azeroth will be consumed by the flame.
Tier 2: Onyxia, Blackwing Lair. While the daughter of Deathwing rules the kingdom of Stormwind in human guise, her brother amasses an army of brutal orcs, dark dragons, and experimental new breeds of draconian horror with which to conquer the world. Unmasked, Onyxia escapes to her lair deep in the Marshes of Dustwallow, where the hordes of draconic children she has spawned swarm to devour any foolish enough to pursue. Meanwhile, Nefarian watches from his perch above Blackrock Spire, impregnable fastness of the Dark Horde, as his minions gather for their final assault upon the dominion of mortals. Do there exist among those mortals any bold enough to strike back, or is this Azeroth’s final hour? BWAHAHAHAHA!
Tier 2.5: Ahn’Qiraj. (Yes, point five. Keep that in mind.) Deep within the forgotten sands of Silithus, an ancient evil remembered only by the immortal stirs. The eldritch God of Evil, C’thun, has weakened the bindings shackling him in the heart of the world and resurrected his ancient servants, the Qiraji. Hidden and protected behind the very walls meant to keep them imprisoned, the Qiraji and their Dark God now prepare to restart a thousand year old war to exterminate all life on Azeroth. Only by reassembling an artifact sundered in antiquity and releasing the Qiraji from their prison do the mortal races stand any chance of winning this war, and to do so they must unite as one and pierce through the Qiraji hordes to the center of their power, there to assault the Dark God of Evil himself before he is able to break free and plunge the world once more into eternal night. Holy fucking shit.
Tier 3: Naxxramas. As the denizens of Azeroth struggle to recover from the near-destruction of their world, the sun is blotted out by a swarm of floating Necropolises teeming with the undead, an overwhelming invasion force of the Scourge, the frost of Northrend still clinging to their edifices. As wave after wave of the undead break over the defenses of the kingdoms of the living, threatening to cover Azeroth forever in the chill of the grave, a small band of heroes must take the ultimate risk, penetrating the great Necropolis of Naxxramas and seeking out the Archlich Kel’Thuzad, engineer of the Scourge Invasion, second in stature only to the Lich King himself. It will take a miracle to overwhelm the defenses of Naxxramas, but unless the greatest of the Lich King’s servants can be defeated, death will rule Azeroth forever. Omgah.
It used to be that a content patch was the whole package. Epic backstory, world in peril, exciting and extravagant scapes of fantasy and horror, and finally a legendary battle against a force that, unless defeated in this very battle, will destroy all life and happiness and kittens and everything. It was an entire saga unto itself. Sometimes there was an entire new tier of gear to collect along the way, but sometimes (AQ) there wasn’t. Tier 2 was all the more epic for it.
And then Blizzard stopped writing their story in terms of content patches and began writing it in terms of expansions. Take a look at the raiding tiers in TBC real quick.
Tier 4: Karazhan, Gruul, Mags. Hey, we think there’s a demon living in this tower that sort of used to belong to us, will you get him out of there? Oh and there’s this monster up in some mountains where no one lives who likes to eat the dragons who like to eat us, maybe you should kill him so the dragons will eat us more. Also the evil orcs who mostly keep to themselves in that wasteland up there have a pet demon, maybe you should set it free and then kill it. Erm, because, that’s why. Demons and monsters suck, amirite?
Tier 5: SSC, TK. Oh my fuck, there are snakes draining a nearby swamp! Unless you kill them, the entire fish population of the bayou could die! Plus, an elf stole a spaceship from the wind-chime aliens you’ve never heard of before, why don’t you get it back for them? I mean, it’s not like the world is in peril, what else have you got to do?
Tier 6: Hyjal, BT. Man, those fish and wind-chime aliens were pretty grateful. NOW LET’S GO BACK IN FUCKIN TIME! Oh, no reason, it just sounds cool, you don’t actually change the outcome (we won that war anyway, go us!), but there is seriously nobody threatening the world, and you look bored as shit. Oh, Illidan, the crazy guy who’s locked himself in a shitty castle nobody lives near and just sits in it all day being crazy? I don’t really think he’s a threat per s- er, I mean no, you’re right, he’s about to *cough* destroy the world, or something. Go kill him.
Tier 6.5: Sunwell Plateau. While the armies of Azeroth are off FOR NO GOOD REASON ON ANOTHER PLANET DICKING AROUND, Kil’jaeden the Deceiver, Eredar Lord of the Burning Legion, begins to open a portal into Azeroth through the remnants of the Sunwell. Demons swarm over the high home of the elves, burning shit and enslaving dragons, preparing for the moment when their master will follow them through the portal and herald a new age of flame and nothingness for Azeroth. Against all odds, the heroes and armies of Azeroth return to the planet they live on just in time to battle their way through the demonic hordes of the Sunwell Plateau and reach the Sunwell itself just as Kil’jaeden begins to pass through and, using some random-feeling shit that turns them into dragons, they push him back through. He’s not, you know, dead, but he’s definitely not coming through this portal.
Okay, fine, Q, if you say it like that, it sounds stupid. But these weren’t supposed to be individual stories like pre-TBC tiers, it was all part of one larger tale about the interconnectivity of the Illidan and Burning Legion storylines and the latter’s plan to use the resources of the former (Kael) to invade Azeroth again. See? Backstory, world in peril, strange new scapes, and ultimately a battle against a terrible force that, unless destroyed right this second, will end all life. Fits all criteria.
Yes, that’s my point. Unlike the self-contained epic sagas of pre-TBC, the content tiers in TBC were chapters of a larger story. But, leaving aside arguments about whether that larger story even held up to the original sagas of pre-TBC, do you remember how unsatisfying it was along the way? How purposeless and discardable Kara, Gruul, Mags, SSC, TK, and Hyjal felt when you were doing them? Black Temple sort of wrapped up a story and was a pretty epic instance, and Sunwell provided the “oh, so that’s what this story is about” moment for the expansion, but everything up to then? After saving the entire world four times in a row 10 levels ago, spending months and months assaulting some sort-of-a-threat villain’s lieutenants on another planet was a pretty big letdown.
So, Wrath. Starts out a little stronger. First, we’re back on our planet, which is once again in peril. Second, the over-arching story and ultimate villain of said story are clear from the start, so the mincey lieutenant-killing we do along the way doesn’t seem like a complete non sequitur. Still, there are problems.
Tier 7: Naxx, Malygos, Sarth. Remember when you guys saved the world that fourth time? Well yeah, you didn’t, actually an npc did that. Plus, the exact same dungeon is now attacking a city, and you have to go do the exact same shit you (didn’t) do a few years ago again. All because (not you) didn’t destroy a phylactery, which you, being wiser, also don’t do this time. Plus another dragon has gone crazy, and you have to go kill him while he yells arrogantly but emptily at you. Also plus, you can sneak into a dragon portal underneath a dragon temple and, without any prompting or a hint of guilt, slaughter the dragon you find there as well as the children it is protecting. You know, if you want. No reason to. But you could.
Tier 8: Ulduar. There is an exception to every rule. Out of nowhere, a tier of content that is, once again, its own self-contained epic saga. An ancient prison broken, its ancient warden driven mad by the whisperings of the God of Death. Beneath the snowy peaks of the northern reaches, the world’s oldest evil gathers, its jailors turned to pawns, its prison made a fortress. The forces of the epic floating magic city ally with the heroes of Azeroth to battle to the center of the ancient Titan compound of Ulduar, free its guardians from their corruption, sidestep the deceptions of Yogg’Saron and, with the help of the ancient Titan Wardens, slay the God of Death. Meanwhile, the Titans have sent their herald to Azeroth to determine whether it should be destroyed. He determines it should, until the champions of the mortal races penetrate to Ulduar’s secret chambers, fight him, and convince to spare them as well as to feel remorse for the thousands of planets he’s condemned to the fire in the past. Epic, and satisfying. The best story yet.
Wow, Ulduar! I have to admit, my hopes are pretty high, maybe content patches actually mean something again! Let’s see what’s up next…

Oh, balls!
Tier 9: ToC. You ready for something truly epic? How about a raiding tier that is comprised of a single room, a few supremely uninspired and story-less encounters, and absolutely no danger to anything. World in peril? It’s a goddamn tournament, wherein you fight to prove (because killing some animals, a demon, doing some pvp, and killing a few trash mobs > saving the world 7 or 8 times) that you’re worthy of doing the actual fighting to save the world. Remember when you saved the world that third time, and it wasn’t quite worth calling it a new raiding tier? This one instance, with one room, five meaningless bosses, and absolutely zero lasting story events, apparently is.

Welcome to Tier 9, where heroism is just a spell. FFS.