I mean, I suppose Iron Man wears one to, sort of... but making Hawkeye maskless kind of makes Cap look wimpy... like he's the only little kid riding bikes whose mother made him wear a helmet.
And then there's the fact that (so far) it just doesn't look that good. I've always been curious why they don't do more with prosthetics when making super-hero masks. Between old-age make-up, monster make-up, aliens, etc, you'd think sculpting a form-fitting mask that didn't look like a big clunky piece of rubber wouldn't be that difficult. Yes, it would mean hours in the make-up chair for the actors, but if they're willing to do that for those other genres I don't see why they can't do it for super-hero flicks.
