Remember when epics were epic?
I remember when the loot system was terrible.
I remember when raiding required too many consumables.
I remember farming and farming and farming for resist gear.
I remember when epics were epic in the sense that they were incredibly hard to get. Perhaps too hard? Maybe?
Here's the fundamental problem: we all want to be unique heroes. We want to save the world. We want to be awesome. But everything is relative. When I save the world, I feel awesome. When you save the world, I lose some of my unique awesomeness. Objectively what I did is the same, but comparatively I am worse off.
Those at the top like stratification. It's what puts them at the top. Those at the bottom tend to not like it so much; or sometimes they don't mind it, but they wish they could move up. Mobility though, that makes the top vulnerable, they might stay at the top, but it will be crowded.
Vanilla had a pretty lonely top. WotLK has a more crowded top. BC was somewhere in the middle. Those at the top get angry as they see others rise to their level. They often did the same thing, just a little bit slower, but still, they were once the inferior and now they are not anymore. That's a hard adjustment.
Maybe it's impossible to balance. We all want to be at the top and we all don't want to be at the bottom, but with no bottom there is no top. We can't all get what we want on a relative scale.
This has led to the great irony: As WoW became more casual, I've seen more and more elitism. People used to know where they stood. They were in a raiding guild and that meant something; their guild had killed C'thun or KT and that meant something; they had a PvP rank, especially a high one, and that meant something. No one needed to say anything, so often they did not. It wasn't some enlightened time with no conflict, there was plenty, but we didn't have such urgent need to put down the other person to prove ourselves.
These days there's not quite as much to distinguish us. Everyone has done Naxx, or at least I imagine anyone who has cared and tried. Ulduar, people have cleared mostly (I've never killed Yogg-Saron or the general guy). The distinctions between players aren't so clear. So we make up new ones. We have gearscore and achievement links and we obsess over tank health and healer mana and we desperately try to prove that we are better than the next person over.
No one is immune to this, some just choose different paths to assert their virtual superiority.