People need to realise PR has existed far longer than anyone ever thought it would, so the fact we've got a Season 17, and maybe a Season 18 there-after, be it American/European/live-action/animated/whatever, is something we need to be grateful of.
The fact Disney still gives enough of a **** to fire and replace the EP is a good thing in my eyes. This guy was obviously doing something wrong, in Disney's eyes, and it's nothing to do with how "dark" RPM is, because they wouldn't have greenlit the 18 episodes before his removal.
Side-note: "dark" is the hyperbole of the year, no doubt about it.