Why is the bathroom sink outside of the bathroom in many motel and hotel rooms?

To accomodate those guests who need to do something at a sink, but don't want to intrude on their suitemates in the bathroom. Think about it. If you're traveling with someone you either don't know particularly well (like group travel) or someone you know well but either don't want to see in the bathroom or is a chronic bathroom hog, it's not going to be pleasant for you if the only sink is in the bathroom. So many hotels and motels put the sink outside (or have two sinks - one in and one out) and only leave in the bathroom the things that shouldn't be publicly accessible at all times.  more