Agree, that is a great rant.
Ellison was definitely brilliant, especially when it came to short stories and some TV episodes. But he was never “great” because he was also extremely difficult and disagreeable.
He was also kind of like Forrest Gump. In the 60s and 70s, he seemed to turn up everywhere. Fun fact: He once got into it with Frank Sinatra.
https://en.wikipedia.org/wiki/Frank_Sinatra_Has_a_Cold
He was a great short story writer