Am I the only one to think they completely fucked her over in X/Y?

She could've done more, as well as her relation with Malvia, and the fact she was with Team Flare.

They could've made a plot reveal that Malvia was working with TF and Diantha and her pokemon were trying to stop it, and you had to help. They could've done more with her than-

-Hi, I'm Diantha, and I know the Prof
-Hi, I'm Diantha, I'm the champion
-Hi, have a Ralts and a Pebble, Bye