The people who are unhappy with themselves end up producing so much damage. And when someone is feeling miserable about their own life they try to spread it and "infect" others with their drama and negative behavior. It is sad and I wish those people would get the right help to change their mindset. I avoid them though, just like you do. I think it is also useles to try to change them. A person will never listen when being attacked or told that they are wrong. Naysayers will always exist. It's about our own attitude when it comes to this. I just close my mind when I see people trying to bully me or behave badly and I learned to leave them to the Universe. And they are already sad by having to live with themselves already, that is a punishment in itself.