I think that might just be the guys you know Nai. Both my brothers went to boy's schools. My big brother is one of the kindest, most non-confrontational people I know. My little brother isn't as gentle as my older brother but he's generally a decent person.
TBH I think it's my responsibility (and DH's) to teach our sons to respect women not the schools. Maybe families that have less respect for women are more likely to choose boy's schools? I guess I need to think about that. Because when you select a school you're selecting their peers.

I'm kind of torn between the academic and the social. Because most research indicates that both girls and boys do better academically in single gender classes.