Maybe it's a statement about the fundamental nature of humanity. All aspects of our psyches manifest in the Warp, but it's a question of which ones are preeminent. Which parts of humanity drown out the others? I'm sure there are Warp deities of "order" but do they draw enough energy from the human psyche to override the gods of war, desire, despair and scheming?
One of really core reasons why Chaos is, well, Chaos, is War in Heaven. It's presumed that during that before Warp was more... orderly, (or at least supposedly neutral, since I guess various malicious warp beings were a thing before, they just weren't a big deal) and with it the Warp got fucked resulting in waves of nightmares came true and assorted tentacle monsters. There's a chance that current "negative" and "chaotic" nature of warp is not only drawn from contemporary sources, but there's a lot of emotional fallout from back then, and it only gets worse. Snowball effect, really.
Now, the reason why there is no real "counter-force" to this, is the fact that there were no truly "orderly" dominant (as in, widely spread with high population and psychical capabilities) beings in Galaxy for long time. Old Ones were more like hippies and by extension Eldar were also really "loose" before the whole Slannesh debacle. Necrons don't really count for obvious reasons, Orks work in weird ways, which leaves us with humanity, which wasn't hardcore fascist order uber alles dudes for essentially their entire history up until Emperor slapped their shit together for a Great Crusade.
Tau are irrelevant.Here's my beef:
The canon asserts that "like kinds of emotional emanations" condense together, such that there are rivers of hate, flows of despair-- et al.
The thing is, if there is a unifying characteristic of the entire imperium of man, it is hope of the emperor's providence, and faith in his immortality.
The same rules that spawn chaos gods should therefore be actively congealing into a god-body comprised of those things, whether the emperor wants it or not.
Which might be totally happening in some fashion - the thing is, it's complicated because Emperor is technically still alive. I mean, there are some clues in form of existence of Sanguinor, the whole Legion of the Damned thing, various miracles of faith that are being pulled off, which imply that hardcore faith does have a real effect (most commonly for Sororitas, but there's a chance those things happen much more commonly, they're just overlooked). As I said though, it's complicated because Emperor is still a being that's tied to his body. It might be that the "orderly" emotions are channeled towards him but he's not a pure Warp being, which constrains him and makes him working the same as Chaos Gods impossible.
I think we can overrule the former, because if that were true, then chaos would have already won (handily).
Which may have happened (we just don't know yet), or may not, or maybe fucking Alpharius and Omegon BROKE EVERYTHING FOREVER.
That only leaves option two, which I alluded to cheekily as "Narrative Reasons". AKA, Narrative Fiat, et al.
I mean, this is the entire reason behind everything in Warhammer 40k, but I find trying to explain anything with it is... boring, uninspired and lazy. Sure, it might be the actual real world reason, but if you use this explanation for something, a question appears as to why you don't just explain everything with it, and then the next question would be "what's the point then?".Trying to make sense out of imaginary universe is a neat exercise for mind, and just going "well but muh writers" you're kinda taking away the whole point.
That origin hasn't been canon for years. He has no backstory beyond having existed for a long time now. He's just an incredibly powerful psyker of unknown origin, same as Malcador was.
The guy couldn't even create the primarchs without getting extra energy from the Chaos Gods and couldn't fix the corruptions the Gods put into the primarchs and marines as revenge for being stiffed on the deal.
The fact that he hasn't reincarnated himself but instead gave instructions on how to turn the Throne to a life support system instead of it's original function indicates that he can't bring himself back.
"Hasn't been canon for years", yeah so are tons of things in Warhammer lore which are considered true. Unless a piece of fluff specifically says "this isn't true" or overrides the old canon, old canon is still in effect (and even then, since everything is true, it's just a matter of perspective, he might still very well be even if official fluff states that, say, Imperium believes he's an omnipotent God that created everything and were first). The Primarch creation thing is... weird, but doesn't necessarily mean his previous origin story is false - after all Primarchs are a bit more than "lmao genetically engineered dudes", and being the result of psychic fart of thousands of shamans doesn't mean you have infinite powers. Also, Primarches and marines weren't per-se corrupted by Chaos Gods initially. They were "destined" to do certain things, but said destiny wasn't... exact, and the "game" could be changed immensely quite easily. Consult "The Board is Set".
There's also the issue of how Big E came to exist in the first place: The canon storyline involves a cabaal of shamanic leaders willingly terminating themselves, and redirecting all of their energies into reincarnation of a single birth; the result of which was Big E.
We have overwhelmingly more energy being pumped into Big E each day than was used to spawn him. It should be painlessly trivial for Big E to reincarnate himself. Why is he choosing to die?
Now, this is problematic. My two working theories I can come up with on the fly are:
a) Emperor decision to be sat on the Golden Throne, which was presumably caused by him not wanting to abandon humanity for the time it'd take him to somehow return (if he could back then) somehow bound him to the thing, and he can't fucking leave. I mean, the thing was an actual gate into Webway, which kind-of harnesses Warp and binds it into something that doesn't try to rape you, so he might be bound in similar way.
b) Getting wounded by fucking Horus that's all pumped on Chaos Gods juice isn't the same as getting wounded regularly. Perpetuals, which are the immortal dudes that hang around the lore are apparently vulnerable to being killed by Fulgurite, which was basically a piece of Emperor lightning juice, though only when handled by Primarches.