I was reading a great blog a while ago (though not that great if I can't remember in retrospect) that artists weren't always so SQUEAMISH about bulges like they are now. The gist was "what does it say about us when we accept grotesquely built bodies but shy away from even the barest realistic detail in the crotch? What poor mutilated things our heroes are now!"
I cannot help but agree. Blame the puritanical U.S.? Other than that, I got nothin'