But that's the point people are making, that his credentials actually aren't relevant, at least not to the extent he's an expert. He worked at Blizzard, but not as a developer, it's been likened to someone who worked in the billing department at a hospital weighing in on medical care.
He does have experience as a dev on Heartbound, but that's not AAA, and he seems to have got bored of that, preferring the ego boost of being a streamer.
He's still entitled to an opinion of course, but it shouldn't carry the weight it had been given.
His support for life services makes sense when you find out the game publisher he (allegedly) founded and the one he recently resigned from, was publishing live service games.
He claims he was review bombed, others have checked the steam stats and it didn't support his claim.
It seems like you want to give him the benefit of the doubt, and TBH that's fair enough, especially if you're just going to ignore him. Like I said, I think a lot of people who are mad at him were following him, and feel like they were taken for chumps.
If you did decide to dig into it though (and I'm not recommending it), there are some content creators bringing receipts, and there is a definite pattern of behaviour.