Thats kinda like saying that since you are going to drive your car into a bridge abuttment at 80mph anyway grow your hair longer and you'll have a better chance of surviving a serious head injury
thanks to the extra padding.
If longer hair could give me anywhere close to a 65% chance of walking away from an otherwise fatal accident, I'd grow a fro' and beard like Jerry Garcia!!! I'm not saying that the behavior that transmits HIV is anything other than destructive of self and society, but it sounds like circumcision might be a meaningful advantage to give a child just in case of what they might grow up into.