>>42581133
Her motivation is extremely petty and childish.
Her personality is just snooty asshole.
Her evil actions are just pressuring Sci-Twi.
She immediately gets replaced by Cadance afterwards.

The worst part of it is that this could've absolutely worked if instead of Cinch they had used Sombra instead. Because Sombra had just as little plot and generic motivatrions in the show at the time, too.