Good catch Lurk. I hated most of his gimmicks when I become familiar with him in the 90s but he was a creative force . I enjoyed his account of when he interviewed with Stephanie for a job on the WWE writing team, she walks into the room holding his resume and says something along the lines of “Tell me about your creative experience in the wrestling industry.”
While I saw him train many times, I never actually talked to him. But I am/was friendly with some of the old mid card talent and we talk/ed (sometimes one of the big "stars" would be around), but I have never heard anyone say anything bad about Sullivan. But I was told that he always resented that Dungeon of Doom gimmick/stable he was given. He had been thinking of retiring from in ring activity for a while and then was given that awful gimmick that basically just came down to everyone that WCW couldn't find anything to do with were stuck under him hoping that something would happen. Instead all that happened was that turd of a match with the cages stacked on top of each other and, like.., 150 wrestlers against just Hogan and Savage. Which of course Hogan won,.. by pinning Flair out of all people even though Flair wasn't a member of the Dungeon of Doom. Kevin didn't want that turd to be his last match and angle he was known for so he started feud with Brian Pillman that was supposed to end in a retirement match (that Sullivan was going to lose) but instead after a PPV at what would have been the midpoint of the feud, Pillman revealed Sullivan as the booker and was "fired" by Bischoff. This is the famous angle where Pillman asked for his release in order to legitimately make it look like he was fired and Bischoff was stupid enough to believe that Pillman was going to lay low and come back. Instead Pillman got his release while hanging around ECW and then ran straight to WWF/E. So the feud was moved over to Chris Benoit to retire Sullivan. (And steal his wife)
But the dude could book and write storylines for sure. Certainly better than Dusty Rhodes or Ole Anderson.