Some people can't manage
So let me get this right, programmers leaving obscene comments is an argument for not commenting? Nonsense. I've run my share of programming teams, and ANY programmer who put obscene comments in the code, let alone left them in the final version, would find out very quickly that it wasn't appreciated.
Sensible commenting IS an enormous aid when you have to take over someone else's code. I've been there, done that, far too often in my contract days to be convinced otherwise.