Nothing wrong with being angry, and you can read 'bitter' into Ellison's take if you have to, but more like somebody with good critical standards who expects better from his so=called peers.
Ok, I draw my "bitter" remark from the available evidence. 40+ years, whining about COTEOF.
As for having critical standards, again, that is something I can completely understand. But int he real world we have a thing called acting professional, and he certainly seems to be sorely lacking in professionalism or impulse control. He gets away with, and gets a pass from people for acting like a child having a tantrum ONLY because of his name.
The problem I see with that is it just validates him since he's never accountable for his behavior.