Maybe not so much applying to games, but any sort of fictional narrative should definitely not be spoiled by anyone by revealing surprises or plot points out of context of the narrative itself. Some of the best gaming experiences I've had (BIOSHOCK!) would have been diluted severely had I been privy the various surprises and plot twists prior to experiencing them myself. One of the best parts about being absorbed into fiction, is the freedom for the audience to guess completely for themselves where the plot will progress to; they will think about it after they've stopped reading/playing/whatever and they may even think about it randomly out of excitement. The moment when either your speculations have been confirmed or denied; the moment when you recollect all relevant clues and piece them together in your head (sometimes you guess the second before you're told) is one of the most satisfying experiences a narrative can provide. This sense of satisfaction is dulled if the individual subjected to the story has their own liberty to interpret the narrative as they wish; if someone says to you "at the end of the book, someone dies, but I won't spoil it for you by saying who", that puts your mind on a fixed track. Where before you may have considered many possibilities and verified them with your own opinions, now you don't need to experiment and explore; YOU KNOW WHAT'S GOING TO HAPPEN. Even if the plot twist is obvious - there is always an ambiguity in where the story will take you next, that we relish, and plot twists are even more satisfying if you're sure you know what's going to happen and you're completely wrong!!
My point is, you cannot argue that spoilers do not tarnish gaming or any other experiences because there is no-one who would rather hear it from someone else than experience it for themselves.
My point is, you cannot argue that spoilers do not tarnish gaming or any other experiences because there is no-one who would rather hear it from someone else than experience it for themselves.