Everyone's so focused about the hype and that it couldn't match expectations, that they don't discuss why the core concepts of No Man's Sky don't and can't make for a fun game on themselves.
And as someone who has pretty much avoided the hype because I think I understood that from the get-go, I think it's a real let down because this game tried something everybody thought they wanted, but no one really wanted.
Starting off with procedurally generated everything - this doesn't make for a fun game. When everything happens all at the same time, you just get chaos with no cause or goal - and therefore, in the large scheme of things, you as a player have no consequence on the world even if you could affect a certain thing - planet or animal or otherwise - as that thing happening already exists in the world, just in a different place. It just makes everything seem pointless, and while sightseeing tours can be fun in short bursts (like walking simulators), they can't engage unless they're telling a story and have actual direction.
Proceeding with the vastness - vastness isn't a good thing. The "bigger" your game is, the larger is the average amount of time the player has to spend between every piece of unique content. Whether it be grinding or sailing (in The Wind Waker) or space flight (NMS), you're just wasting everybody's time. That's not to say if everything in a single game were compacted into a singular point in time it would've been better - there's a fitting length for every game - but if you're advertising bigness over actual content, you're just promoting mindless busywork.
That's just the problem I've had with Bethesda games. Big overworld, lots of quests, but a lot of dead in between times where you're just grinding and walking through a mostly desolate world. I know it's an uncommon opinion, but I find all of them boring. There's probably a way to make a game that feels big but isn't and just funnels the player to new content at every turn, like an "open world" game with an Ironman mode and a timer, so you can't wander off too far without being pressured into reaching your objective. There are probably other ways to accomplish the same goal, like using the art design for that - the vistas in Half Life 2's episodes are a prime example for that. But I'm getting off topic.
The combat in NMS seemed especially iffy from the trailers, because it was just point-and-shoot. No cover, no smart AI, not anything. This sort of "whoever has the best gun wins" without any consideration to player skill and only to player progression just reeks of a grindfest. At the time I didn't know you could upgrade you weapon by just wandering around and stumbling upon a schematic, but it's just the same busywork - instead of fighting mindlessly, you're walking/flying mindlessly to your next objective. It's just boring by definition.
Also, they're an indie mobile studio tackling the most insane premise you could think of. Expected performance issues aside, the principles of modern mobile gaming just do not apply to serious gaming - whether it be the "choose your own adventure without understanding a word" (RNG with artificial choice elements) or mining/fighting (click to win), it's just badly designed. And it's not the fault of Hello Games either - it's the fault of the entire mobile industry, which is flooded with crap targeting and preying upon casual gamers and non gamers.
With those 4 things in my mind, I didn't think once it's going to interest me or become a good game in my opinion. With no hype or expectations, there is no outrage. BULLET AVOIDED.