Since the game plays _just_ _fine_ without a connection to "the servers" (at least on PS/4) because it's not WoW in space, the presence of item 2 on this list tells me that you've never actually played this game. "The Servers" in No Man's Sky are just data repositories for the discoveries you upload, and the chance to download other peoples discoveries if you find anybody else's planet. There's no "instancing" because your machine is the instance.
Meanwhile, I have not seen a single broken promise in the game. I don't know what the munchkin power-gamer types _thought_ they were buying... but what I got was pretty much exactly what I was sold: An exploration and survival sandbox game with a rich story that you have to "discover" (by reading the texts you farm out of ancient monoliths and ruins).
Now I know the people who didn't pay attention to what was being sold are quite disappointed because they were thinking they were getting Destiny "life full of boomstick!" redux. But go find me a single video from the makers that tried to sell that at all. They talked about exploring worlds, mining, crafting, and dodging sentinels.
Is the game flawless? Fuck no. It's essentially impossible to find your way back along your flight path to that one planet that had that one resource that you desperately need, and ibid for finding your way back to an on-planet trade hub. So the mapping and waypointing needs some work. And I can see signs of bigger things that got waylaid (like observatories that talk about locations in distant space that, instead, direct you to far-away points on the planet you are on), but I suspect that that became a question of things simplified in play-testing.
So I agree with the parts of your sentiment that "you pay your money and you take your chance", but I disagree with any part of anybody's complaint if they are bitching about "the servers" and the lack of WoW-in-space behaviors.
I've yet to see a single complaint that really boils down to a broken promise. I've seen a lot of complaining about things that were fully disclosed in the advanced coverage where the complainer took great liberties with their imagination, insisting that what they were promised was not delivered. But those undelivered promises seem to be entirely in their heads.