You also often see bathroom doors that open in; I had this random conversation with someone at a conference last year. I assume the theory is (assuming there is one) that there would rarely be so many people crammed in a bathroom that there'd be such a crush to get out that it would be hazardous. On the other hand, even day-to-day bathrooms are sometimes located such that someone quickly walking down the hall looking at their phone could fairly easily be slammed into by a door being swung out into the hallway.