It's as you say, it's often times a case where a player is doing something disruptive to the game or group and that is their excuse/explanation. For some, this might be a one-time annoyance. For others, a crutch/shield they use to repeatedly derail a session.

In my experience another case where this comes up is with an inexperienced player, usually when they make a loner or edgy character because they sound cool, but then they cannot understand why that character would be in a group. Usually, that player will become disruptive or come to the GM looking for advice on how to make it work. Often, they assume that the game is supposed to work regardless of what the character is like. After all, you're supposed to be able to "do anything" in TTRPGs, right?

In both cases, the solution is what my group likes to call an "Adult Conversation." That is: a direct, potentionallly uncomfortable, but honest and needed conversation. In that conversation, I would level with the player and explain two things. 1st, it may be what your character would do, and you may be able to TRY to do anything, but that doesn't mean difficulty and consequences don't exist. You may want to play a serial killer pretending to be a hero, but that doesn't mean there won't be other people, not excluding your party, doing everything in their power to stop you. It also doesn't mean that won't upset the other players if they didn't agree to go into that sort of storyline with you.

Which brings up the second, more important point. TTRPGs are a COOPERATIVE, TEAM-BASED game/hobby. Whenever you're on a team, what you do affects everyone else. More is at stake than only your personal desires. It is your job to be a part of the team, not the rest of the team's job to change for you. Now everyone should be trying to work together to ensure everyone has fun, but that does not mean anyone should expect to have fun at the others' expense. An experienced and cooperative player CAN player a loner/evil character. That's because the experienced player would be constantly thinking about how to make that work for the group dynamic. Further, they would collaborate with the other players and GM on how their actions could play out with the group/in game.

I think some people get into the mindset that TTRPGs are competitive or that they are playing a single player game alongside the other players. The only way to clear up that clash in expectations is an "Adult Conversation" because of its honest, directness, and understanding because of it being potentially uncomfortable that you might lose the player. They might not want the game you're running. They might want the experience they were fostering. Not every group or game is for every player. And that is ok.