It's not that I think they're homophobic as such… it's more that careless ways of disliking slash often ends up using words that are de facto sounding homophobic even if that's not the intent. Such as "that could/should never happen", "it's just wrong for him to be with a man" and that kind of thing. The sentiment is usually character driven, but it sounds bad :-/
Link found: http://tanous.livejournal.com/737.html

Also, I very much agree that threesomes can solve a lot! :-D