I am curious. What specific aspects of male socialization lead to their belief that they are entitled to sex?
I mean it's obviously #NotAllMen but there definitely is a broad spectrum of problematic (at least) male attitudes toward sex in societies around the world that range from things like passive aggressive resentment toward being "friendzoned" all the time to aggressive serial rapists (though that crime, it must be stressed, has a lot more to do with asserting power and yes, entitlement, which is expressed through sexual assault rather than merely being about sex per se). With plenty of things in between.
But yeah, plenty of men have healthy attitudes toward sex. That doesn't mean that what we're discussing here isn't a real social problem. Certainly there's a biological element to it, but I'm not at all convinced that there isn't a lot of unhealthy socialization involved as well. And like I said, it's a spectrum; for a lot of men these attitudes aren't black or white. Very complicated, like dead0man said (however ironically).