No reason to argue about stopping at a stop light or not either. You can always learn the hard way. I saw it last season in the mountains. A nice fellow had come all the way from Belgium and carried a big pack for three weeks with about 20K of pro digital camera gear in it. Latest and greatest lenses, carefully protected with cheap fogged-up filters. The end result: he would have gotten sharper pictures using a five dollar disposable cardboard camera.
Interesting. But aside one or two polarizers I have not yet come across any fogged filter, aside of course being fogged from being stored in those plastic cases witzh polyether foam. The latter may have fogged a filter over decades. But that is just a matter of cleaning.
Well, one specific cheap filter I am extremely grateful for is the one the past owner of my Fuji 69 rangefinder kept over the lens the entire time. It was hazed and scratched like crazy, and not doubt caused every single shot to be miserably compromised. But it took me only five seconds to cure by throwing that off-brand UV filter into the trashcan. The lens itself was immaculate, as if it were brand new - not even any dust.