@tmenzel

If you're *paying* to play a game, then I don't think it's selfish to play the style that you want. We're not talking about, say, the military where everybody needs to work as a team or somebody dies, IRL. When I want to tank, I jump on my DK. But when I get tired of it, or the knuckleheads I find in LFG, I jump on my Warlock and nobody bugs me to tank. It's my $15/month, and it's not selfish for me to want to spend it however I want.

I do agree, however, that adding more tanking classes may increase the pool of available tanks, provided that people actually pick those roles and enjoy them. But in a pinch, somebody may be pressured by the group to change roles, however I'm not sure how often that would happen.

I somewhat agree with the OP regarding complexity; Blizzard has made strides to make things simpler for new players, but more could still be done. Some classes I stay away from because there's just too many damn abilities. And there's tons of abilities that are very situational. It gets annoying to have two or three additional action bars of abilities that you "might" need to use as some point.