Nyk,
This is a wonderful piece. Thank you for it.
I actually read this about a week ago and it's been bouncing around in my mind since then. One idea that I keep coming back to is the difference between additive morality and subtractive morality.
It's a crude distinction and I haven't heard it called under these specific terms before, but in a nutshell, subtractive morality is about subtracting the negative you do, while additive morality is about adding positive.
It occurs to me that subtractive morality is very fertile grounds for psychopathology. Because it is easy to fall into the trap of consistently finding more and more harm in your own existence.
The net result is expending huge amounts of energy to fix an endless litany of sins, in the hope that one day you'll be perfect enough to do no harm, and by doing so, finally be acceptable to others.
Except of course it's not possible to be that perfect, and even if it was, people have the capacity to invent new wrongs to suit their goals. If you're inclined towards self-loathing there is always some new aspect of yourself you can find to hate, and to worry about how horrible it will be if others see it. So what starts off as a reasonable moral sense can become a bottomless pit of recrimination. It's the zealotry that you refer to.
I think a functioning society requires a certain baseline level of forgiveness for small wrongs - an agreement that some insults aren't worth hating each other over. That baseline exists naturally between people who trust each other (and sometimes it's set far too high). In recent years though, as the animosity between (and within) groups on each side of the political spectrum grows, that baseline has disappeared and our culture has become increasingly more toxic.
I know this is optimistic but I see some hopeful signs that the worst of it is slowly burning itself out. People can only tolerate the poison of zealotry for so long before they begin to ask questions.
Best wishes,
J