I'm with you. Not to mention the way that being "born that way" normativizes both gender and sexual binaries in a way that is not at all true to biology. This is one of the most frustrating paradigms I've come up against--frustrating in part because I am sympathetic to the impetus behind it. But I really think that the vastly greater number of gay and straight men who insist you're born either one way or the other versus the greater number of lesbians and straight women who say that sexuality is fluid to them has to tell you that the former position must have to do with policing masculinity... I think.