You do realize that Isa’s need to be perfect is just a mask to hide the stresses in doing so 24/7 which took a toll on her emotional state much like Luisa. And since Mirabel was the black sheep of the family, Isa had to jump on the band wagon to keep up the facade. But she got better in the end.
Scar not so much. Scar is one of the most beloved and most effective villain in the disney animation Canon next to Maleficent, Jafar, and Ursula. The whole reason he acts the way he does is that he is bitterly jealous of Mufasa for getting more love and attention in the Pride lands and Simba for stealing the throne from him which led him to murder Mufasa and exile Simba pinning the blame on him.
And for the record, being violent and spoiled is kind of major traits in villains as a whole. That like saying “I don’t like water because it’s wet”. If your going to tell people that you don’t like a character, you’re going to have to give a better reason than just “their mean”.