Problems with past RV Parks you've stayed at?

I stayed at a nice RV park last week and it was a very nice park. But what irked me greatly was their rules had a disparagement clause saying the campers could not say anything negative about the park. I don't think they could sue you for saying something negative, if it's true, but all the same I would rather stay somewhere else that does not have such an extreme rule. Negative and false = bad. Negative and true - we still have freedom of speech.