Well sure, except you need to understand that these idiots are incapable of considering the circumstances. Good guys by current day moral standards? Fuck no. Good guys in the sense that everything else in the galaxy wants humanity dead and has been trying pretty hard for the past 15,000 years or so, yeah.Also the discourse around "no good guys in 40k" thing has kicked up again, which I always found bizarre. Only the Imperium is working towards a future where humans exist, so in my books they're the (relative) good guys despite all the genocide, slavery, etc
"But human slavery, and fascism"
These people don't know that dark eldar want to turn you into an ever living cuck chair for their own amusement after raping you to death a few dozen times. They don't know that chaos worship makes you grow tentacles and shit if the gods actually like you enough, assuming you don't get eaten and damned to an eternity of torment first. They don't understand that tyranids want to scour the galaxy of all biomass, or that most necrons want to eliminate everything from what they consider their lawn with weaponry that slowly disintegrates you at a molecular level. It's more like
"Oooh, kink elves. Chaos, fight the power! Look at the cute bugs! Oh, it's like The Terminator except they aren't Arnold" is about the surface level understanding these people have of the setting.