I don't think Justman was being overbearing or insulting. As anyone who's read The Making of Star Trek
should know, Justman and other ST staffers wrote their memos with tongue firmly in cheek. It's a jokey, playful tone, part of the way the people doing this busy, stressful job let off steam and had fun.
Ellison's pseudonym was Cordwainer Bird, which was partly in honor of Cordwainer Smith, the pseudonym author Paul M. A. Linebarger used on his science fiction. He used the Bird pseudonym as sort of his personal Alan Smithee, when he wanted to take his name off of something in protest. So it's odd that he left his real name on "City" when he's been protesting about it ever since.