Not in my experience. Liberals criticize their parties and communities constantly, at least in the circles I know. The criticism is most often about treatment if others in ways that don’t affect the person themself. Sometimes it even seems like status seeking and gets obnoxious. But I’ll take a movement where status can be had by advocating for others over over where it comes from selfishness.
So this is saying Palestine originated with Nazis and Soviet-style communists. I guess some people just missed all that critical thinking we keep trying to put in the education.