I think there's plenty of room in the gaming eco-system for non-combat games - they're more niche, but there's a market.
The problem here is that No Man's Sky was trying to be a swiss-army knife out of the gate - exploration, huge combat, building, survival, discovery (and the meta game, race to the center!) - but it only does each of those things *kind of*. Crafting is okay but not particularly rewarding. Combat is trivial and boring, surviving the elements is easy, and because of the size of the universe discovery feels meaningless outside of the in-game credits you get. It cost them more money than it needed to, and also caused them to distribute their resources and not fully flesh out any one system.
I actually had the thought the other day that the game would be *better* if they tore out all of the combat. It's boring, trivial, and only serves as a "fucking shit, now I have to deal with this" obstacle between you and the thing you actually want to do.
Even space-flight is sort of a weird space-simulator/arcade hybrid mechanic. It's a game that isn't sure what it's trying to be, imo. And that was the issue. Sean Murray had all of these fantastic ideas ahead of time, and I think he felt like he was just musing with the fans about **a** space game, and not necessarily the game he was going to make. The poster who compared him to Molyneux hit the nail on the head.