That's his unique personality. It's never been Wanda's.
She mind manipulated some of the Avengers (and seemingly gave them a vision of their future), but she did not do it out of malice. She was under the interpretation that they were dangerous and caused what happened to her family. She was mislead. She wasn't evil. When she realized she was wrong, she changed.
And I personally can live without Whedon's misogyny while pretending to be feminist bs.