The problem is that violent rapists know that what they're doing is a crime. They know they'll go to jail if they get caught. There's nothing you can do to make them stop raping people except catch them and lock them up. Seeing as you can't stop the criminal, the only logical choice is to educate the victims in ways to avoid being targeted.

Of course you should be able to wear whatever you want without the threat of being raped, I don't think anyone disagrees with that. Hell, you should be able to walk naked through the most dangerous neighborhoods and not be touched. But the fact is that you can't, because while most people are decent, there's a very small percentage of people who are just fucked in the head.

You can apply the same logic to other crimes - if everyone was a good person, banks could leave their safes wide open and let people stroll in for a look around, no problem. But they can't, because someone would take advantage of that situation and steal shit. The bank isn't 'asking' to be robbed, but had they taken precautions, they would have been at a much lower risk.

Of course, this doesn't apply to people who simply misunderstand when what they're doing becomes rape. The drunk teenagers who step over the line because of ignorance or inebriation are the ones who benefit from being educated in what is and isn't rape, and that's great. But just as you can't stop a bank robbery by explaining to the criminal how bank robbing is bad, you can't stop a violent rape by explaining how rape is bad.

As you said, men and boys are able to not rape, in fact almost all of us don't, and have as much hatred for rapists as women do. But the ones that are fucked up in the head aren't going to listen as you explain that your clothes don't make you a target while they're ripping them off. I believe that people are improving as a whole, and there will be a time when this isn't an issue anymore, but until then, 'better safe than sorry' seems like the most logical approach to me.