Stalker wasn't a game designed for the whole world to enjoy. It was a game designed by a ussr oldfag for ussr oldfags. It was meant to give that that shitty nostalgic feeling. I remember playing Stalker for the first time, when I walked to an abandoned bus stop and my first thought was "WOW, it look just like a bus stop I used to walk by as a child".
One of the multistory building looked just like an old abandoned multistory building we have on the outskirts of town, that nobody cares to destroy or rebuild. And the whole game is filled with such little "easter eggs" (if you even can call them that), that are meant to be near and dear to Ukrainians and other post soviet folks. I still don't really get why it used to be popular in the west, as they don't get the SOUL
of that game.
Also, the creator of the game could not decide if they were going to set the game in Ukraine or USSR. All signs set it to be Ukraine, but the currency in the game is soviet rubles (you can tell them from russian rubles by the picture of Lenin on them). I believe that was a mistake by them and they should have fully went to use modern Ukraine as the setting, because soviet rubles look just stupid.
>just see Slavs on various imageboards claiming that it is a thing
Don't bother. They just want to feel special. You might as well claim to have american soul with just the same level of commitment to it.