I hear this a lot. I see the screen shots and it is a little funny in some cases. I know that there is text that comes across the wrong way. It happens. But honestly, some people just want to argue, debate, and have the last word. If you are not going to work with someone, just say that, and move on. It really is that simple.
Unless this is a predator, scammer, or fraud, you don’t know that this person is really someone to spread the word not to work with. You can give someone insight but, unless you have firsthand accounts on things, you better just steer clear. Assemble the facts for presentation. Make sure you have all of them before making this sort of post or call out. You never know if they might try to go after you for slander or libel.