Completely disagree. Nice/kind/good are synonyms and sets of good behaviours. If you can not tell the difference between a good/nice person and a not good/nice person that does not mean good/nice people do not exist, that means you have a problem understanding people and decent behavior. I think people who say "nice guys are not nice" simply are not very good people and it threatens them to know their are people who are consistently nice so they need to tear them down. They also get off on the drama. I seriously hope being nice, polite, good is not being "cancelled".