Actually they both changed. Followed them both since 2008 and NC up until the huge fiasco in 2017... or 2016? When I lost all respect for him.
The difference is, James Rolfe (AVGN) pretty much did all his videos save for maybe a few friend cameo things here and there. He kept it down to simple reviews and commentary things and kept a low profile with low-drama. Save for that "Not seeing the New Ghostbusters" that drew alot of ire from the crazy SJWs of twitter..
Doug Walker (Nostalgia Critic) made ALOT more mistakes. He tried to create an empire alternative to Youtube, managing a bunch of creators. He also employed two people to take care of it, one which ended up being a sex-addict weirdo (Mike Ellis) and the other a certified douchebag that didn't know how to run shit and got him to sign over all exclusive rights to the Nostalgia Critic (BAD FUCKIN MOVE) Mike Michaud. Naturally with that many people drama ensued and it was poorly taken care of.
People were not paid or respected for their time maintaining the site. There was a weird rule-system and Doug was at the top, abusing power/woefully ignorant of shit. Like, hey you can't review the same movie or talk shit about the Nostalgia Critic or offer any critique that goes against the grain. Plus the whole, possible pedos of the unnamed dude and Jewario wanting a harem of tweens/rape fetish (which probably lead to his suicide).
He also didn't know shit about film-making and basically made 4 shitty long films that didnt pay,feed,water or compensate workers in any way possible for his vanity project. Anyways, it accumulated over years then exploded in a horrible mess all over the internet.
The kicker was how Doug reacted, which was pretty much nothing. No apologies, no trying to fix things - just shut up and keep his head low as his boss (Michaud) commanded. There was a half-ass "We're sorry you felt that way" response and that was about it.