i think a lot of girls are scared to train seriously because they have the sneaking suspicion that they could be a lot stronger and have more muscular development than a lot of guys they see working out in their gym. their notion of femininity requires that they be weaker and smaller so they steer clear of the weights or restrict themselves to the tiny dumbbells.
part of it is about 'what man will want me?' and not wanting to restrict their options, i guess. a little self confidence would probably go a long way.
i once saw a guy laugh at his girlfriend when she went to pick up the 5kg dumbbells 'that will be far too heavy for you - here, take these' as he handed her the 1kg. she took them and expressed admiration as he played with the 5kg. pathetic, i know, but girls are typically socialized to smooth the male ego rather than focusing on their own ability / achievement.
i think there is a significant change in mindset for women who decide that they do not care if they become stronger than the majority of those guys. their ego can take the dipshits calling them men and making penis jokes about them etc.
so a girl who trains to kick a guys ass and is proud of the fact that she can...
i think there is a lot to like about that. from guys who appreciate a women who can express genuine appreciation / admiration for their strength. from girls who can come to learn that they can be the strongest / fittest / most muscular them they can be - and be more beautifully feminine in virtue of that.