What I mean by that, is that the personality profiles used for demons have them all being "every demon for himself" in behavior, with subjugation and subservience to more powerful demons/beings being the norm down there. Given that they are immortal, cannot reproduce, but still somehow exist in limitless numbers, there MUST be some kind of social order down there. The most likely being small fiefdoms ruled by a central power figure, with less powerful minions held in thrall. I would expect to find such enclaves in the hell layer.
I think "there MUST be some kind of social order down there" is dubious. There certainly could be, in some cases; but remember that DF is intended to procedurally generate all sorts of different fantasy realms. We simply don't have enough data on life as a creature that is not merely freed from the constraints of biology, but has never experienced them.
How much of not just human history, but of all life we know, is dominated by the need to eat, the drive to reproduce, and the fear of death? How much has been driven by the great gears of evolution... does this behavior make you more likely to breed before you die, and for your offspring to breed after you?
I seem to recall some interesting research on the biological benefits of altruism, family & clan relationships, etc.; much of it came down to indirectly helping genes *like* yours pass on. A creature that was created by godly or magical fiat, with no need or opportunity to breed, no heritage before or after, no genes, no need to eat, sleep, breed, age... would they even understand the *concept* of a society, let alone form one?
Of course, some fantasy (and actual historical religion) sub-genres have elaborate pantheons, hundreds of hells or layers, and so on. DF should be capable of generating those, and more; one world might have something bureaucratic and vaguely Chinese, another D&D + Planescape inspired, yet another pure creatures of crawling chaos. Social structure should be *possible*, and should be procedurally generated to be interesting; but it shouldn't be assumed to be "human-like" for such disparate creatures.
I understand the point you are trying to make, but remember that I myself am asexually oriented, and dont have a reproductive urge. This lack does not inhibit my ability to be a part of society.
You are overlooking other aspects that are already present in the game that give insight into demonic behavioral patterns. For instance, when they do escape the hell layer and set up shop on the surface, they pose as gods to win over human minions, and use brutality to dominate goblin minions. Since these beings have no drive for reproduction, do not eat or sleep, and thus have no real need for material wealth, the remaining motivators are purely psychological. The same motivators that drive demons to take minions on the surface would drive them to take minions in hell.
You are fixating on human-centric drives, and avoiding purely emotional/mental drives. Demons take minions, because it makes them feel powerful, and thus makes them feel good. It has nothing to do with sex, nothing to do with reproduction, and food needs have no bearing. All that's left on maslow's pyramid is safety, and self-actualization. Those are the only motivators that would govern the behavior of such entities.
given that they display a penchant for dominating lesser beings out of an apparent psychological or emotional drive to feel superior, they are highly unlikey to avoid conflict with each other, unless some form of pecking order gets established, and each demon knows where it stands in that heirarchy. There are likely to be frequent shifts of "loyalty" (I dont think they have a concept of this. more "obedience" actually), which upset power balances, which would make demon politics quite interesting.
I mentioned that the demons do not reproduce but maintain limitless numbers. Since demons CAN die, and kiling a powerful rival to cement dominance seems par the course in surface demon interactions, then some form of ad-hoc social structure must exist to prevent the demons from going all "highlander" on each other, even if this simply boils down to powerful demons commading thier underlings not to kill each other (because dead underlings dont genuflect, supplicate, or obey, and thus dont stroke any egos.)
your deconstruction essentially comes from a faulted premise. I do not say they must have a social order because of biological things. I say they must have one to avoid there being just one super demon in hell.