Someone tell me the point of having a mouse with so many buttons unless you're a professional Starcraft player?
I think it's just MMO players that "need" that many buttons. I find it awkward to use nuber keys beyond 5 and the F-keys in general, just because you have to take your fingers off WASD (and I'd have to look, because even after all these years I can't find them reliably

). With a 10+ skill bar I'd probably find them useful, too.
Starcraft players do most of the complicated stuff with hotkeys.