Yup, this is my feelings on the matter too.

I make for a good tank, but I prefer only doing dungeons to help friends. It's not about being the center of attention or something, I'm just tired of hearing my girlfriend shouting about having to heal idiot tanks. ;) I'm good at the role, but I don't find it much fun in bosses on raids.

Healing, same thing, I do it to help out friends if they need it. Otherwise it's not really my "preferred" role. It can be a little annoying because even the greatest healer can't save stupid.

DPS, I enjoy melee DPS (Monk inparticular) because it's in the fray, in the thick of things. It's hectic and especially with monk you're always moving, always doing something, there's always the push to keep your stacks up, while NOT DYING. As far as being a soloist who dislikes responsibility though, hell no. I want mechanics that rely on me to do something, I know I can depend on myself to do it right, and if it means every time I have to run the fire out of the raid for the group to succeed, so be it and all the better really.

See OP, here's a thing about DPS, and especially melee; You're always avoiding stuff. A good melee player has a really high level of awareness, not that healers or ranged don't have awareness, but when a caster has to move, it's jarring, it pushes them out of whatever they're casting and they HAVE to move, it interrupts them, catches them off guard. It's an irregular part of the pattern. Melee? It's just part of our job, it's expected, it's natural. Hell, for monk it's part of our little punching dance.

The other part as far as Support DPS goes, I'd love to play a support DPS, I just don't really like how Bard feels, so I'm looking forward to Machinist. But I'll still level up my monk too, and my tank, and healer. Cause it's great to be able to fill a role and be dependable!

I think putting short labels like "Tanks are egotists, healers are nurturing mothers, DPS are selfish introverts", that's way, way, way too simplified and doesn't begin to scrape the top of the cake. Frankly, everyone will have different reasons for doing what they do. Are there some tanks that just want to be the focus? Sure, are there some DPS that just don't want responsibility? Yeah, although in an MMO everyone is responsible for something at some point. I mean, you can really tell the difference in a dungeon run when you have 2 garbage DPS vs 2 wonderful DPS, right?