Wow! You seem to be willing to tarnish all males simply because they happen to be the same sex as the majority of violent criminals. Do you not understand? That’s what sexism is! Or are you just sexist and proud of it?
The chances of an individual male leaping into someone else’s changing cubicle and attacking them, in such circumstances, with staff only yards away, is staggeringly small. And if such a person really wanted to commit a violent crime against women, there would be hundreds of easier ways to do it elsewhere, with far less risk.
Is a male more likely to commit such as offence than a female? Possibly. But what if I told you that black people were slightly more likely than white people to commit such an offence? Would that justify excluding black people from the fitting rooms? Of course not! That would be racist. Just as what you are condoning, is sexist. And sexism is no better than racism.