Things in lunar orbit do degrade and crash into the moon. NASA has put a lot of stuff into lunar orbit over the years and they all eventually crashed. There's

Things in lunar orbit do degrade and crash into the moon. NASA has put a lot of stuff into lunar orbit over the years and they all eventually crashed. There's essentially no atmosphere, but the Moon is not a perfect sphere and there are mascons that perturb orbits. It's a question of how high it is, too. NB: I didn't know this until I asked /r/space about it several years ago.