That's a horrible idea. If they were to remove No Man's Sky from GOG, then the devs would stop providing any updates to the GOG version of this game.
And thus everyone who has already bought it would be getting shafted a lot worse than they already are in relation to any of the allegedly DRM-gated content that is being complained about in this thread.
I respect your view.
1) Time4Tea's suggestion does not call for unconditional removal. His other option is that "(what he calls) DRM is removed".
2) Delisting a game does not mean that it has to stop receiving updates (just like having a game listed on GOG does mean that it actually receives updates available on other stores). There are games on GOG that are no longer for sale, yet continue to receive updates (though, admittedly, not many).
3) The question is what is more important to you (and to others), having updates for this game, or not having any single-player features
locked behind online-only walls in any game on GOG. For me, the latter is more important.