A fascinating question because I used to intentionally make my characters Mary Sues. As a former child who used to write, for a while I never understood why people would give character traits they disagree with to the character or characters who are supposed to represent what is right in your world, since they’re the ones unfolding the story’s solution. This had the side effect of my main character being nicer than me, and sometimes my parents would remark to me “why can’t you be like your main character”, which had the side effect of putting me on the fast track to self-improvement. Anyone else?
I write about bad guys. All my characters are bad guys. One is greedy and manipulative, whereas the other one is a violent sociopath, while the other is a womaniser and finally a thrill junkie who loves to watch people get beat up. I’m working on the aspect that the sociopath and thrill junkie are also serial arsonists.
I don’t agree with what my characters do, but they represent an untold story. I have little interest in making my characters likeable and instead more like the person they are supposed to be. Bad guys.
There is something likeable in people that stick to their guns no matter what, though. I can respect a crazy, unlikeable bastard that doesn’t go easy on someone because of some societal norm.