heres my 2cents
like most i dont think there is a need to hike your trunks up your crack to show how shredded your glutes are(as well as picking them out after )
but bodybuilding is suppose to be about total conditioning. not just the major muscles.... but all. ripped glutes and hams show that you have nailed your dieting.
someone said that you dont have to see a guys shreded glutes to know hes in shape. that may be true but wouldnt a guy standing next to that guy who also has shredded glutes and hams look to be more in shape. and that might be the deciding factor on placing one ahead of the other.
dieting has evolved and gotten crazier thus allowing more competitors to achieve shredded glutes. this is probably why you see it now rather than in the 70's and 80's and so it has become part of judging.
I agree with blinky in that if you have two competitors who are evenly matched in all other areas you have to find the one body part that is more detailed on one guy than the other guy. In many cases its the glutes, hamstrings or both. When you reach the highest levels of competition, everyone is going to be ripped. Everyone has big arms, chests, shoulders, backs, and quads. So judges have to nit pick on how detailed one competitor's physique is over another. Thats where the hams and glutes come in. It has nothing to do with homosexuality or heterosexuality. If this is a moral issue for some of you, then you should not be fans of bodybuilding because it is all about vanity which is supposed to be one of the seven deadly sins anyway.