"The mechanics were varied and interesting and just challenging enough to be difficult without being infuriating."
This right here is what I see as the problem, Blizzard got so infatuated with designing for for top end guilds they ignored the majority of their playerbase.
Sad part is Blizzard has no concept of moderation so I fully expect MOP to swing in the opposite direction too far.

Tone down the mechanics a notch and get rid of too much trash, that would be my design choice.

I don't think there is a "too far" in the opposite direction, especially after Blizzard managed to drive off a million customers in the space of what, half an expansion? The main draw of WoW has always been its accessibility--even when said accessibility was only really relative to Everquest.

Making MoP more Wrath than Wrath (so to speak) could only be a good thing. The only problem I can see is that many of those who left probably don't want to come back--too little too late, etc.

@rolly the trash of karazhan was also part of its strength. It was thematically appropriate to whichever wing it inhabited, and it required strategy and execution but it didn't chew up a ton of time.

@blayze I agree. I understand the desires of hardcore gamers to have content that only they can complete so that they can have bragging rights, but that era of wow might just have to over.

Kara was truly amazing in its look and feel. The haunted castle full of ghosts and powerful entities... even now it's fun just to walk through the place. It just has so much flavor and character. Raid mechanics and difficulty levels be damned, it's still one of my favorite instances.

Every thing from the random book buffs to the encounters was just full of fun theming. Opera Event was just brilliant and would still be brilliant even if they revamped it and added some "hard mode" mechanics to it. It has that much flavor.

@Blayze
Sorry, my comments weren't clear enough. I was refering to what they did in Cata raids not Kara. Kara was difficult but not infuriating. It had the correct balance.

It's also important to remember that once Kara dropped badges and new badge gear came out, running Kara became a decent source of gear upgrade for people. A slow trickle to be sure, but still something. Never underestimate people taking the easiest path they can for gear. I have no doubt some people were running it because they enjoyed the play, but I think there were a fair number of people running it just for easy access to badge gear.