You're saying they are the same culture. They aren't. It's more like a vinn diagram they intersect but are not the same. Spoiler culture also intersects with books as I know too well and with movie culture, as I also know too well. And youtube thumbnails spoil as many movies as they do games. We all remember the endgame fiasco, I'm sure. Books are mostly immune from digital spoilers but aunt Margaret is a bitch and hates me so I usually hear the end of some books before I read them and book clubs suffer from at least one mouthy member or two that read faster than the rest of us.

gaming culture favors people who play games, gym culture favors those who are athletic, car culture favors mechanics, and so on and so on and so on... if you aren't a mechanic, why go to a car meet? If you aren't interested in being athletic, why go to a gym? My point is you've entered into a culture you don't like and then question why you're there. Sure, I get that it leaks on to gaming culture more heavily than movies or books, but it's each of our own obligations to avoid spoilers for ourselves. It's rough, but it's the life we live.

Maybe it was my adhd but I never finished the game either. I got caught up hunting for hours on end and making a nuisance of myself until I burned myself out. But you're right there is an issue with how loose lipped people can be with games. Couldn't tell you how to fix it outside of taking breaks from social media while playing.

An honest answer is I think games stress the story less then the experience. And so does the community at large. A lot of games have a story only as an excuse to play the game(gta, saints row, far cry) that isnt always the case some games are heavily reliant on the story (last of us) but it's much harder to stumble across spoilers for games like that. The feeling of going though the story is better for me personally if I know the ending or how my choices affect that ending. I don't like surprises.