I think the biggest source of Moralism is due to a fairly recent traumatic experience I had with Spiritual Abuse with being part of Fundamentalist Catholicism, and their belief in Eternal Damnation for committing mortal sins without going to confession before I died. Plus there was so much emphasis on them being the one true religion, and that their doctrines and dogmas were unquestionably right and the rest were wrong. I saw in the "True" Catholics like those who followed the teachings to the very letter were extremely self righteous, dour, judgmental, draconian and had a major guilt complex on themselves(also known as false humility). They often used justifications that people were too evil to understand right from wrong, and too stupid to understand true justice.
So I find that I hate anything that resembles Spiritual abuse whether its A) Authoritarianism of any sort where one is expected to surrender their will and intuitions to another authority, B) Use of intimidation through threats of punishment or violence, or scolding C) Criticism, correcting, lecturing or reprimanding that was not asked for, D) Authoritarian personalities who submit to the powers, and act like it is their moral duty to enforce this authority onto others, or E) Ideologies that treat people as incompetent, and therefore undeserving of being treated with dignity.
I get easily annoyed when workplaces, families, governments, schools, religions, social groups or cultures behave in such a fashion.