>Attribution is important but it's impossible to know all the literature that is out there and even when you've tried your best to seek out prior arts there is always a possibility that you've missed something or not understood the connection with something previously read.

It's not like Schmidhuber's papers are obscure.

>I've always thought that Schmidhuber was toxically uncharitable - what is the point of accusing and blaming

You're engaging in toxic victim-shaming. What, you expect him to just bend over and accept people stealing his ideas without giving him credit? Fundamentally the researchers who stole from him were engaging in unethical behaviour and shouldn't be allowed to get away with that without consequence.