Yes, rental DVD's are treated very poorly by some people. Seems to be a prevalent attitude "Its not mine so why look after it". Teenagers are the worst, watch one, chuck the disk on the table (play side down) put another one in and back to the couch. Seen some that looked like they had been shuffled like a pack of cards, and another with ring marks on it from a drink container
One shop I used to go to specifically told customers playing in playstation type machines was Verboten, as the disk is vertical and gets damage during insertion and removal and they would be charged extra if it was.
I have a couple of players here, the cheapy balks at anything just not spotless but my old Akai will play anything short of Vinyl
Bill