Damn right son, we murdered women and children before, what's the difference now? At least they are used for something.
Bit hypocritical to be talking about being some kind of noble freedom fighter whilst parading the badge of a legion that turned for literal shits and giggles.
The nihilism caused by comming to the realization that two hundred years of war and exterminations were done in the name of lies, and what that level of disillusionment would do is pretty significant. We're literally talking about warriors who exterminated entire populations for not measuring up to a metric they discovered was measurably false. So no, it's not really hypocritical, they're committing similar sorts of acts of brutality, just for more selfish reasons as opposed for a cause based on bullshit.
Where did the word 'noble' ever come into the equation? No one in the Warhammer verse is noble, but Chaos is the closest thing to freedom. Good and evil have long since become irrelevant, it's just what degree of slavery you subscribe to.
Basically this quote I murdered thousands for the Emperor and he gave me nothing except his damning silence. Now his lapdogs yap for every life I take, while the gods promise me the galaxy.
Outside of the impulse to fight, Orks are probably the closest thing to freedom. At least life on most Imperial worlds, more or less are somewhat like ours, you work a job, have a family and enjoy your hobbies. Where as Chaos, save becoming a literal slave to the Dark Eldar, is slavery and pain. Unless you've gained some measure of power, you might as well expect to be food... Actually strike that, unless you become a Daemon prince, you become food for the warp no matter what. Short of ascension, you literally can't win, enjoy that mostly short brutal life, Traitors...
Life on a Hive World is basically slavery in a poluted hellhole. Though your arogant posturing is comendable, for a thick skulled Imperial, it's actually not terribly accurate. In an earlier novel, despite the authors hatred of Chaos, in Daemon World we saw a rather functional society, even if it was prone to violent change (which is a fact of life Imperial societies share) it had cities, tribes, and temples where life was not much different from your average feudal world. In the Night Lord's second novel they stopped by a Crimson Corsair station with a civilian population going about their business. Things are not as black and white as you've delluded yourself into believing.
Well I said life on most worlds, many of the more "important" worlds in the Imperium are a straight up drag to live on, the closer you live and deal with authority, the less freedoms you get to enjoy and the more extreme everything becomes. Hives indeed are a more amplified 2000AD, but considering much of Hive life is so beneath the Imperium, there is in fact actual freedom there, it just happens to be honest and brutal freedom. But when you take into consideration that many of the Imperium's worlds are based around farming and manufacture, its just dull and unassuming. We can also talk about the many Feudal, Feral and Death worlds, worlds which have even less contact with the Imperium and it's extremism, you just have small scale human extremism at that point And despite what you say, life under Chaos is brutal and is dictated by that domains patron, life there doesn't even really allow you to enjoy being human, there is very little upward advancement and as I said, unless you become a Daemon prince, you lose no matter what you do, you'll be sucked into your gods domain in the warp and feed them. Enjoy being magical poop ;D
What's different from the usual? Do you believe the Emperor has some golden palace in the sky that he ushers you to when you die? an amusing thought, but much like the rosarius itself such stories of faith defending the soul are more often then not a lie to protect the unwashed masses. To be an ork is to be enslaved to your genetic code, what point is there to joy with no suffering to contrast? what use is an existence with such a limited palette of emotions? There is none, in Chaos your emotions can transform you into whatever you are at your core. Your sins are written plainly on your flesh, for good or for ill, and through those sins you can become something more then what the Emperor enslaved you to be. The warp is heaven, it is hell, it is salvation, and damnation. Without it humanity is nothing, because the warp is humanity itself made manifest. If your existence in Chaos is pain then it is because you make it so, for the Dark Prince pain is pleasure anyway.