You know, if everyone is so worried about boys and girls having sex in the bathroom, maybe its the straight people having sex in bathrooms that are the problem?
Also, about kids getting "confused", kids won't even care, most likely. This would probably ease confusion for a lot of kids.
Becoming a teenager is a vulnerable stage of your life. Boys and girls become curious about each other, and may do silly things like look underneath the stalls to check what they can see. This will probably break the self-esteem of the victim, especially since they are so sensitive about their bodies. I can just imagine what boys will do with a girls sanitary bin in the bathroom if they have the chance and loud remarks from either boys or girls when other people are in the stalls :( All in all: not good for psychosocial development.