In this situation, I'd say you're worse than a Rimworld monster. Sure you may butcher humans and pawn off their organs, skin, and meat, but you don't wipe out hostile factions by way of complete genocide. You attack their colonies, kill the defenders, and those who remain scatter, their chain of command broken and now unable to organize against you properly.
In Starsector? If you sat bomb a planet, you are wiping out all life on it. And this is on a planetary scale, meaning you're killing thousands of times more people than you ever did in Rimworld. And if we add in the fact everyone in the Persean Sector are trapped there after the Collapse, what you're doing is akin to dooming the human race.
If you don't like being genocidal, there's options if you don't mind using mods. Nexerelin lets you conquer planets instead and, assuming you're not commissioned to any faction, you can give up control of them to allies. I like giving conquered worlds over to Tri-Tachyon so I can get more of their post-crisis accessibility bonus.
