Yes, again I agree, but those people weren't saying anything. They just dismissed the comment and down voted it and went on their way. Nothing gained at all because of using words that everyone knows will cause this reaction. Shotgun meet foot.
You make generalizing statements like “everyone knows”.
I genuinely don’t understand what kind of reaction you think “everyone knows”. That some people will be inexplicably scared when the the name of Karl Marx is invoked?