Mind the gap

I'm always puzzled about the gap around doors in public toilets in North America. I've been told it's so people can see if it's occupied. Really? In the UK and Ireland, it's easy to determine if there's anyone in there without having to see exactly what they're doing; I'd like to avoid that and it's unnerving if you make eye contact. Check the lock indicator - green for empty. Push gently on the door - you'll soon find out if someone has simply forgotten to lock it! Peer under the door - can you see feet? Of course, many fail carry out any of these checks and stand outside empty cubicles until I come along!