What was traditionally a girl's/woman's bike was designed for skirts, but now is retro because it looks cute as a cruiser bike. They were much weaker designs than what men had.
Regular bikes now come in "women specific" styles which look the same as men's but have measurement of the frame certain components adjusted for the differences in bodies.
For mountain biking, you'd never want to ride a cruiser type frame.
Of course women wear stiletto heals with no practicality (except to get a guy's attention) and they'll ride cruisers because they look cute. If it get's them riding, who's to complain?
