Demons being the spawn of human thoughts or whatever is something I've heard about but given Strange Journey states they existed before humans did, I find that idea kinda suspect. Although each SMT game apart from 1 and 2 takes place in a different universe so maybe the rules are different.

And of course Nocturne was big on how the Demi-Fiend couldn't change anything or have a Reason of his own which doesn't really make sense. As I recall, SMT still goes with the fallen angel myth of Lucifer. He was with YHWH but then rebelled which of course means he changed.

I've noted this before but Persona isn't as different from SMT as one might think. In Persona's constant challenging of authority and insistence on individualism (taken up to 11 in P5), I see SMT Neutral. Neutral and Chaos have both been treated more fairly than Law ever has so far as I know. I can tell you that in Nocturne at least that True Demon (which is basically Chaos) has far more effort and thought put into it than any of the other routes.