Eh ? But you aren't living in the outside world. You are living in exactly that storm in a teacup.
Doom and Gloom
But you can just walk away from the whole clusterfuck. Hell, that's exactly what the protagonist in CoP did.
Well, Strelok stopping the zone from expanding further sure as hell took some of the danger of the zone away. But that's why SoC is the most atmospheric and gloomy stalker.
Yet the characters usually have some reason to be in there.
You have bandits that are a combination of people with nowhere else to go or simply desperate enough to seek richness in a man made hellhole, a shitload of government assets trying to understand and contain the situation, Holla Forums + /k/ trying to exterminate Holla Forums and various subspecies of normalfags LARPing Fallout. It's not really all that grimdark. I mean, no less than going to a war torn shithole would be.
How is wartorn + nuclear waste + the zone + mutants not grimdark ?
What more does it have to be ? Not that I know much about stalker, but the theme is on the grim side from an outsider's perspective.
It may not be the level of doom and gloom you want but Brandish is pretty dreary.
No idea what he wants either, stalker is about as gloomy as you can get and it has one of the best atmospheres in games in general.
Oh shit, I didn't know they remade it for the PSP. I only played the SNES version, that looks pretty good.
Go play Shadow Tower/Kings Field and E.Y.E OP