I look at it as, the libshit mentality of, "Never let a disaster go to waste."
I think they're feeding off whats going on with cute jabs at Sakana as a way to boost views and get people to watch them.
Ultimately it means nothing to Sakana. he is still in charge and he is still making money.
Every donation you give, he gets a cut.
Every ad revenue from you watching, he gets a cut.
Every subscription, he gets a gut.
Every merchandise, gets that cut.
Any kind of jab at him is meaningless.
You're correct that they'd be better off going on their own. The fanbase would follow and they'd be able to get it all with no cut.
The problem is a lot of these people I genuinely don't think are capable of functioning without management. They would need to find someone to manage them - which they could do and probably pay a cheaper cut to and actually be bosses of them meaning they could fire them if they don't like them.