You'll have to be more specific on which Nostalgia Critic movie. There's Kickassia which was the catalyst for the increased amount of sketch humor and overall autism and To Boldly Flee, which was a 3 and a half hour ego trip dedicated to ending the Nostalgia Critic character. Either one is awful.
I remember that too, but the spectacular thing is that none of it stuck for very long. I can remember when it started with people bitching about the fact he crowdfunded his movie, calling it "e-begging" and claiming he didn't need that much money to make a movie. That stopped after the movie came out, and even though I keep hearing the movie wasn't good, people shut their mouths after that.
There was the Cheetahmen II controversy where he and NES Pat teamed with one of the original programmers to crowdfund a "complete" Cheetahmen II, when neither of them were aware the game was technically somewhat finished just horribly buggy.
Then there was the Ghostbusters 2016 video where people tried to smear him as a misogynist when he stated he didn't want to review the movie.
The big reason none of this stuck to James in the long run is because he never really responded to any of the drama. Something happened, people bitched, James ignored it, and eventually people forgot why they were mad. James has the patience of a saint; he's never snapped at anyone for being angry at him and he basically never acknowledges drama. It even worked in his favor with the Ghostbusters controversy where people whipped themselves up into a fury only for James to ignore them and make them look insane.
It's worth noting that whatever negativity surrounded him had nothing to do with his main AVGN content, except for maybe crowdfunding the movie, so it was also easy for the fans to ignore.