I can't believe I just read all of that.
If anyone else stumbles in let me paraphrase rockhead so you don't have to waste your time: Having your rectum ruined has been simplified but marrying more than one of the opposite sex is too complicated.
Gay marriage and gay adoptions have created a whole new set of legal problems, so what are a few more problems caused by polygamy?
In fact, it would be fair to say that legalized incest would cause fewer problems than either gay marriage, polygamy or gay couples adopting.