My playthroughs usually start with me being nice, then as I learn which characters I care about, what things I want and how people react to me being evil I become more and more of a "murder hobo" as you so eloquently put.

As an example, in baldurs gate three I usually gaslight wyll into believing karlach is a devil so that he'll kill her and I get a sweet piece of armour. My whole reason for doing this is that I find karlach annoying and the armour is pretty cool looking (and can be sold if I'm not using it)

Same with astarion, killed off immediately because hes annoying, I like him best when he's comically evil lo

Edit: same with scratch lol. Don't like dogs what can I say