I usually believe emphasis on diversity is a bunch of PC shit that distracts from the core tenants of building a good business (i.e. shipping a product, having ethics, making sustainable profit, etc.), but you really should hire women. That is, you should have a balance of sexes on the team (so I guess hire men if you're in a predominately women field). This is because we're human and one of the most engaging things we can do is interact with the opposite sex.

Rather than having to spend money on extremely bs team-building exercises to get your employees to not hate coming to work, just hire a team of balanced sexes. A bit of flirting, imagined sexual tension, and does-she-like-me-what-do-i-feel-about-him goes a long way to creating an atmosphere where employees don't burn out. (Just make sure to hire non-toxic people and avoid the all-guys-are-rapists / all-girls-are-sluts ideological extremists)