I know this is only partially related to this video, but I really hate the excuse of "Well it's really old anyway" when it comes to spoilers. Just because something's old doesn't mean it isn't new to somebody out there. 10 and 20 years from now when the toddlers of today are playing Bioshock on an emulator or PSN/XBLA equivalent, the big twists that everybody today is familiar with are going to be totally new to them. And the impact of those realizations are what made those moments so amazing to us as players when we first experienced them. I think it's really degrading to think that somebody is less deserving of experiencing that same realization for themself just because they made the mistake of being born a few decades "too late." And not only degrading to the player, but to the people who made the game as well. By refusing to let these people discover for themselves the lies in Rapture, we're also systematically disarming the creators of the game from delivering the experience they intended.
In some cases spoiler warnings aren't that big of a deal (knowing the ring is going to make it to Mordor doesn't change how frighteningly outnumbered the Rohan are at Helm's Deep in the Lord of the Rings), but when it comes to MAJOR plot twists like in Bioshock, plot twists that carry an overwhelming about of the dramatic impact of the story, I think we need to not be so dismissive of them.