I think a lot of goodwill towards ROTS comes from the fans which grew up with the Clone Wars animated series.
I hear this a lot, but I don’t think it’s the case. Most people just really enjoy the movie regardless of the EU. Anecdotally I know more people that like the movie better than the show than the other way around.
So strange, as the characters were so much more likeable in CW then any of the live-action Prequels. And CW is no more juvenile in content than a lot of the antics in those films.