I do generalize, but I talk mostly about pve, man vs machine, where machine gets relatively weaker each week.
People claim they want a challenge, yet you don't see anyone pushing for clearing Normal raids in all greens/blues, it's always the next step on the approved ladder Blizzard layed out, that reward you with better gear to move up on the ladder. And they will defend to their dying breath that they are all about the challenge, while everything points to that they are all about killing that next boss so that they can get stronger and in turn make the next step less challenging.
The exception to this rule, like yourself, are those that play for the people you play with. But I have gotten the feeling that most of our kind has moved to Classic for that exact experience.