"I had no compunction over using my power when it was necessary, but neither did I share the zeal for destruction that so many of the Throne’s own servants exhibited. If it had been possible to solve our many problems through the continual application of unrestrained force, then you would have thought that over ten thousand years of trying it we might have had some rather better outcomes."

It's not the lore that asserts the 'fascist' response is justified, that comes from brain-dead chuds "fans" who don't know how to read subtext and take everything they read and see at face value, the lore is pretty clear on this point: the Imperium's problems are its own creation (the entire meta-point of Chaos in the lore) and warfare isn't solving it, merely delaying the inevitable and fueling the crisis

Not until every rebellion stops being chaos or genestealers.

That's not satire, that's just a story of good vs evil

Speaking of genestealers, take them as an example. Nothing about them adds to a satire of fascism

One of the major Genestealer Cults is literally a parody of the pharmaceutical industry and eugenics and a pretty good one at that