It is not just "some people are stupid", that is too small scale thinking. We are constantly assaulted by algorithms trained to manipulate people, trained off of millions of A/B tests and microinteractions, constantly being tweaked using real psychological research and real manipulation techniques. There are real weaknesses in the human mind, and we have to constantly be on guard to avoid them being exploited. For most people it is simply too much effort to go through life and read every comment as if it is trying to trick you. They just want entertainment, and that's totally fair.