I'm against it, and not because it's unmanly or gay or whatever, but because makeup is an asinine, predatory industry built on tearing down consumers' self-esteem to pit people against each other and instill the need to smear DIRT on themselves, at a retail markup that would make Francis Drake draft up protest signs. And no, I don't believe that make-up is only for people who just want to look good for themselves anymore than I believe there are that many people with sore necks in dire need of a good massager. There are already plenty of industries that prey on male insecurity to survive, we don't need one more.
More importantly than the issue of an industry derailing human progress by manipulating society's collective self-image for profit, can I just point out that makeup doesn't actually work? Like, have you ever seen one of those home shopping channels show off some ridiculously expensive powder or cream, gushing about how it's the culmination of all cosmetic science from Egypt forth, and been utterly unable to tell the difference after they put it on? I guess it's better than the '80's when the whole Barnum Bailey look was hot, but... really?