When I and my team stood up to the executive team of a startup I was working for and quit, they offered me this exact non-disparagement gag clause in exchange for any compensation whatsoever.

The reason we quit was because they were taking advantage of us, and we knew we were never going to get paid. We also knew that they would simply lie to whoever it was they were going to replace us with, so we refused to sign the gag.

It was seriously one of the worst companies to work for, and I was darn sure going to make sure that everyone knew it. I value my freedom of speech