It doesn't really kill Quinn's character though: "arrogant and thinking highly of herself while actually pretty stupid" is exactly what Quinn
is
So you could say her behavior is maybe irritating, but pretty consistent.
Of course her behavior is consistent.
She can't behave any other way. She grew up on the streets.
Everything is simple on the streets - show weakness once, it will become known to everyone, and everyone will remember it.
A weak person instantly becomes the object of humiliation and bullying.
Therefore, cruelty and arrogance are in a sense a defense.
Anyone who grew up on the streets knows exactly what I'm talking about.