My main problem with filtering is that you invariably force motorists who have already passed you, to pass you again. That can absolutely trigger rage among some people. Unless of course it's backed up for miles and there's no chance of any car passing you again. But that's why I prefer to take my place in line most of the time. Cars arriving after me (behind me) have not passed me before, so there's none of that "dammit I just passed that guy!!" feelings.

Cyclists don't like slower cyclists to jump ahead of them at stop lights, causing delays for other cyclists who have to pass them again. It's not very courteous to do the same to motorists, either.