Give me an insight into the motive: pushing an occupied bathroom stall's door/others not occupied

It’s even worse than that. You used to be able to use the top of the TP dispenser for your change and other small items. But now these usually have sloping tops, possibly because once or twice, thirty years ago, someone was caught doing lines of coke from the flat and smooth surface of the old fashioned ones. Sometimes there’s no hook, either. For a lot of guys who don’t carry anything with a strap, there’s sometimes no option except the few square inches of flat territory at the back of the toilet–or the floor.

The worst is when you are stuck in an airport for a few hours alone and have to crap. You have to drag your bags with you everywhere, and most likely take the handicapped stall as that’s only one with room for your stuff. Then it’s a matter of avoiding the puddles on the floor (the women’s room may be different but probably not that much).