I think it's generally the same reasons that more women don't pursue male-dominated professions. I think this is typically that there's an established culture,

I think it's generally the same reasons that more women don't pursue male-dominated professions. I think this is typically that there's an established culture, and not fitting in with that culture makes you seem like an oddity or that you've got ulterior motives. Is that man teaching because he needs a job, or because he enjoys teaching? Or does he just want to prey on the girls? Is that woman developing video games because she's a good programmer, or is she just desperate for male attention? The biggest difference is that fewer people see this as a problem when it's affecting men. Culturally men are expected to bear their problems instead of lament them.