I found Negan to be entertaining, prior to Season 9.The thing was Glenn was killed in the comic books, so this is one aspect that they got right. For me it was when they killed off Carl and Rick was taken by some secretive government agency. Then it just got too stupid for me.
The whole Negan part though, I thought that was the most realistic segment of the whole series. I could actually see people taking it to that level because as a species we have already taken it to that level and more so. In comparison to some people from our past, Negan was actually quite reasonable. Never really understood his love of Lucille, but hey whatever floated his boat.