Which of these is worse? They both succeed in making Adolf Hitler look like Mother Teresa, but which one of them is the bigger bitch?
welcome to the wild wacky world of wealth
Worse in terms of writing?
Mom was 1-dimensional irredeemable bitch.
Cinch was an idiot that thought the her No. 1 student will be able to figure out what to do with dangerous uncontrollable magic by simply unleashing it after shitty song. Also she backed off after "Who's gonna believe you?" despite school being 10m away from a bus stop and numerous eyewitnesses with phones.
Cinch is worse.
Cinch was just a lonely old ice queen who was devoted to the one constant victory she could coast off of to validate her inflated ego, whereas DT's mom really had no reason to be such a snob and aggressively bad parent.
Abacus may have almost pushed SciTwi into a cosmic-level school shooter, but the latter's behavior was far worse for much less reason.
That's only her own interpretation of it though, just like she convinced Diamond Tiara that her's was being a little bitch.
As far as canon's concerned on the show, nobody's cutie mark makes them destined to be evil. It's their own fucking fault if they are.