Its just making ourselves feel better, feel more dominant.
If that's how one feels after speaking truth, then it's not coming from a righteous place. I've seen shame come from a different place than that and work positively on occasion. I remember Stephan Molyneux has said something similar saying that using moral arguments is far more effective than using logical arguments.
Again, please don't take the fact that he is now a Trump statist as reason to not see the truth. This would be a form of argument known as "ad-hominem". The truth will often times show up where you least expect it.
Of course, but this isn't quite correct:
It's not about whether one feels righteous but whether one really is. Someone doing all the things you say above obviously isn't.
You have to make sure that you are on solid ethical ground and shame ideally isn't caused by accusation (as in public shaming), but by the realization of wrongdoing which can happen in multiple ways when the truth is exposed.