In my opinion, there is nothing wrong with being a bit angry or jealous sometimes.
You shouldn't throw your rage at the people around you or let your actions be driven by anger alone. But there are a lot of things one can very justly be angry about. I would even argue that some things one should feel angry about. Like when someone is mistreated.
Denying yourself negative emotions is not entirely healthy in my opinion, it's more about the way you act on them (or don't act on them).
While I generally agree with you, I think we have to look at it from the moderators' perspective, too. What are they supposed to do? Deal with the same persons every few weeks until hopefully some of them grow? Moderating a community is already a lot of (often thankless) work. I don't think adding this would help finding and keeping good moderators.
Ultimately it's not only about what is the most fair but about what tools are needed to keep a community running.