Murderhobos Aren't Problem Players

You're simply playing the wrong game.

I'm More A Celery Girlie, But Carrots Will Do

 It's quite easy to forget in all this imagining that when playing games they are ultimately incentivizing you as a player towards certain actions, typically through a reward structure as well as the gameplay itself. For example, randomly off the top my head, a game that both rewards you advancement via engaging/winning physical altercations (typically through killing) and has significant portions of design dedicated to playing out said fights, players should be initiating any/all combats they could perceivably win. If the game wanted you to care about other fictional elements it should model and reward those behaviours additionally/alternatively!

 Thus: A "Murderhobo" is actually playing said game correctly. You're the one wearing cleats at a bowling alley. Knock it off.

 Identifying what a game wants you to be doing as a player can be as simple, even without a strict/clear mechanical reward structure, as seeing what the gameplay centers itself on. That if you assume the  reward is getting to engage the mechanics (because what wild world would it be to sign up for a game where it is actually about NOT playing said game?) then you know immediately what behaviour each game expects out of you.

 And isn't that why we show up to game night? To play the provided game?

Fights Are Fiction

 What really seems to be the issue with the idea of a murderhobo (even in games with less emphasis on physical violence) is that this somehow disrupts the community's lofty ideal of "telling a story," or at least a satisfying one. I'm not exactly sold on the idea that storytelling should be the final/ultimate goal of TTRPGs but I will make the point that so many seem to miss out on with this perspective: Any physical conflict can and likely does contain a narrative.

 Maybe a simple one in some cases, sure, though then again so can a lot of emotional conflicts be quite simple or boiled to a basic structure: Two people want seemingly mutually exclusive outcomes and refuse to compromise. The main difference is that physical altercations are much more decisive. Immediate clarity how a duel went when it's over. Usually not so much for an argument.

 In that clarity you have much easier motivations to follow and can thus display stakes in ways that are not reliant on strictly textual.

 We love Show Don't Tell right? Well fights are all show! You might trade words during one but it is mostly an exchange of blows and the way someone fights or how they look when fighting can convey a lot of meaning behind their relationship, the surrounding context, personality, desires, and more. If you don't know how to express said character elements during combat then perhaps you're not as good at roleplaying as you think you are.

The Nerdy Says: Know Your Role!!

 Some, maybe arguably a majority, of characters are not intensely complex. Even us as people moving through life are not making deeply calculated choices the majority of the time even though we each are certainly complex. And when approaching TTRPGs from a singular, first/third-person baseline assumption of perspective it often means that taking action is the most important and central portion of what we might consider play. Therefore the path of least resistance in taking action (which would ideally also engage the gameplay mechanisms) should be the most desired and most celebrated. The simplest, in other words.

 Not that complexity is impossible in this or even bad but it's always the ones obsessed with story that are sitting around a tavern asking, "What's my motivation?" while murderhobos have already found it and begun applying it liberally in the pursuit of play. And for that reason alone I would much rather have a table full of women thirsting for wanton violence than one overwritten, intricate character backstory…

 Unless we're playing the Overwritten & Intricate Character Backstory TTRPG instead of like Fight City TURBO or Transgender Deathmatch Legend II I guess.