I think there are valid criticisms of RW but there are also ones that work backwards from Peyton or Brees or Brady or Rodgers and say "Do that RW!"
RW has limitations as a QB. He's somehow been able to overcome those limitations to somehow be very efficient in spite of the boners and calamity. Working with Bevell.
I think there are a few criticisms going down -
He's the highest paid player on offense, he should be playing like a potential GOAT candidate in a pass heavy offense.
(Every team has a certain portion of fans that believe this even if they DO have a GOAT candidate. Yes, every QB should be excellent given their salary portion, they aren't, teams find a way to deal.)
His team is constructed specifically to utilize his talents on offense. (It's not)
Marshawn Lynch made him above average. (Yes, and I posit that Marshawn Lynch would have done the exact same thing with Kaep instead of RW. Is Kaep really a better QB than RW though, on the whole, even if he and Lynch running RO would likely have been dynamite? No. RW benefits from a strong running game he participates in. When's the last time he did that?)
Bevell is playing towards RW's abilities all the time, whatever you believe them to be. RW just isn't doing it right. (Certainly wasn't on Sunday. The end of 2015 was everything you could have hoped for and more out of RW, they aren't doing that now. They also aren't running the ball down throats or executing beautiful play actions or having a useful gimmick like Read Option.)
RW needs to take it upon himself to do something different on the field (That's not how any of this works).
RW's personal life is ruining him (Just like how it's ruined every single QB who ever got married ever. Ya'll are worse than fans of Esports riding their teenage heros for chasing their boners instead of practicing 18 hours a day)
Russell Wilson isn't the best QB, he doesn't have to be the best passing QB and driver of the entire offense to prove his worth either. There's a nuance where he must play well for success but he is conditionally bound by what the offense is trying to do and what it's not capable of doing well. So far that's been rushing and blocking. Anyone want to fade a bet that if the running game and OL play better RW wouldnt resemble his prior self? Or if put into a spread passing game with RO always a threat it wouldn't at least be more entertaining and less soul sucking than this?
So yeah, RW needs to play better - he also needs to be put into a position to actually do so rather than expected to capriciously decide he prefers it now. I'm sure RW would love to do things different, he'd rather get kicked in the stomach by coaches and thank them for the character building experience than defend his desire to do things different.
So many people see limitations as road blocks. They'd rather yell at a gate than find out how to deal with it., maybe get around it.