In a MUD I played for a while, there was this one player who didn't seem to care at all about their characters, just like you describe, tooters.
It was RPI and there were strict rules about revealing players-behind-characters and all that, and maybe ~60 active players or so, in different spheres of the game that didn't interact that much... but I could always tell this player's characters within like the first twenty minutes of interacting with them. They were all ridiculous antagonists who always tried weird metagamey ways to get under my skin, and the skin of others. I say metagamey because it wasn't strictly IC, but it was borderline enough not to get caught in the rules. Like, let's say your character had a very close friend named Finn, who died tragically. This person would know that, and then later create a character, stroll up to yours, and be like "Hi, my name is Finn". Or let's say your character knew a famous outlaw and was part of an outlaw group. This guy would create a character and come tell your character (who the player OOCly knows is currently friends with Famous Outlaw) and be like, "Oh yeah, I was there ten years ago when Famous Outlaw was escaping Famous City... the guards surrounded him and killed him. I saw him die."
So this player, right... I later find them go on an OOC rant about how "long-lived" characters have players that are "OOCly-invested in staying alive" and all gang up together with other longer-lived characters.. and basically, to this person, the game was full of a bunch of dinosaurs who were against engaging in any sort of conflict or interesting plots, for fear of character death.
Meanwhile, this person's idea of 'interesting plots' was creating a character who was insane, bulling into an ongoing territorial conflict betwen warring tribes, and telling a bunch of crazy lies in order to get one of the player's frequent antagonist targets (Famous Outlaw) in trouble.
Long story short, I'd much prefer to play with people who care about their characters and care about the stories they're telling, than someone who will cycle psychopathically through a whole series of characters while not caring about them at all.
Let me just tell you I freaking love Famous Outlaw. I loved Famous Outlaw so much that if Famous Outlaw died I would not play the game anymore. Famous Outlaw wasn't even my character but they was inspiring and wonderful. Eventually I sort of quit this game because Probable Psychopath's brand new 80-year-old character met a dramatic death on the highway... while completely unrealistically attempting to get my character's best friend killed. After that I just couldn't handle how stupid the game was anymore, and the fact that Probable Psychopath was playing in a perfectly reasonable way considering how the game worked.
Sometimes I still think about Famous Outlaw and am real-life inspired by things that Famous Outlaw said. Famous Outlaw pulled on my heartstrings forever. Famous Outlaw is a fantasy character in a fantasy world but perfectly meaningful to me.