I think it's telling that the first mention of Sauron in the Hobbit is (an admittedly brief appearance) as the Necromancer, a term that has come to be associated with one who creates an unfeeling, unquestioning army from the dead, creating a place where the only thinking, feeling creature in the Bad Place is the Bad Guy.

We're essentially seeing that same thing but with living organisms in his subsequent works. There is no orc culture outside of his armies because an orc is a biological creation made for the purpose of being in his army. To be orc is to once have been something else, at least in some versions. In others, they are creations from foulness itself, again, Bad Dude's creations for his purposes.

The subordinate nations he calls on are again corrupted, which requires suspending disbelief to accept that you can bad-ify someone with magic. The solution to the story is to remove the corrupting influence (a thing we get to see happen) to make everyone good again. Part of JRR's brain worms is the insistence on Good Hierarchy to oppose the Bad Hierarchy.

I think reading Mordor as a nation-state in the modern sense, and orcs as anything other than a metaphor for man with the humanity subtracted is going to lead to unsatisfying conclusions, when what we are seeing is warlords and what amount to purpose-built biological creations for war. To speak of Mordor society assumes there was one there prior to Sauron.