It's a fucked world but we have to consider 2 things:
1) It's a game, lots of people use it to escape reality which is already depressing for some of us, or can be easily, I don't want to have a void in me just because there's no "ok" (not even good, just neutral) ending and I have to wait 11 more years for cp78
2)Sure CP is basically grimdark but it doesn't lack hope, I think nomads have it pretty honestly, if you check the maps, they're hunted by corpos but they're ultimately free and they like dying as free men, I think that's the epitome of hope.
Also it doesn't excuse the fact that there's no neutral ending, like.. Sure, it's dark, depressing et.c etc., it doesn't -HAVE- to be the world is there to provide challenges and it did and challenged morals, I'm still thinking about the whole soulkilling thing and what really makes us humans.