That's weird, I could swear Faust was the series' writer/creator, and Strong was just there to read lines.
That's the problem with actors, stars or "people" you know, they feel like thy are in there to have some level of authority.
Also they are actors. Their job is to influence an audience by acting, feeling, talking, and read lines. Really that's just that.
Be offended. Laugh. Cry. Scream fuck drumpf. Repeat. Good gurl!
Just be glad it was a cartoon and not a real show. In any live action series that gets popular the actors start using the popularity to leverage more creative control, because usually by that time they have better offers and can threaten to walk. As soon as you start seeing actors credited as Executive Producer or individual episodes as "Written/Directed by *actor name*" it's usually a sign that the show is about to go downhill. At least with a cartoon the producers can just replace a VA with a sound alike if they try to pull that kind of bullshit, which given Tara Strong's personality I don't doubt she'd try.
In the middle ages actors and musicians had the social status of prostitutes and nobody gave a fuck what they thought about anything. I'm starting to think people back then were on to something.