Canada's had a law since the mid-80s that any sport needs to be either co-ed, or have a male league and a female league. So...you literally can't say "Girl parts = no".
that makes sense to me. so you can either go "the most talented will be on the team" in which case it'll be rare for females to join predominantly male teams (at least by the age that it matters) or you have separate leagues altogether. I guess I'm in favor of the first mostly, though. Having male and female leagues leads to stuff like the WNBA. Better to just take the few really physically talented females and have them mix into the team.