... or when you only live with people who think just like you.
The problem with living alone is that there's no one to say, "Dude, you probably shouldn't do that. It's really weird" when you eat a dinner of oatmeal, bacon and beer dressed in a polyester track suit.
Similarly, if you're a post-modern, secular progressive at a university, news media office or in the Administration, chances are good that you're completely surrounded by people who think almost exactly like you. So when you decide that 6', 300# men who dress in women's clothing ought to be allowed to join 12-year-old girls in the restroom, there's no one there to say, "Dude, you probably shouldn't do that. It's really weird."