Well, according to the Steam Hardware Survey [http://store.steampowered.com/hwsurvey], 84% of people using Steam are on Vista/Win7/Win8, which is 88% of people using Steam on Windows (after you remove the OS X/Other categories). XP's share is also dropping more quickly than any other category. I'm going to go ahead and guess that that's probably not entirely accurate in terms of all computers in the world that run Windows, but in terms of the ones that people are going to be running games like the ones mentioned in the OP, it's probably not too far off. If it were, they wouldn't be finally cutting support for it in new games.
And it's not just games that aren't supported. Lots of new hardware doesn't work fully/at all on older OSes at this point. There just aren't drivers or OS-level support for things that didn't exist yet when XP was released. You can use an SSD in XP, but you don't get TRIM, which kind of sucks. You get a hack/workaround instead that isn't as effective, but what do you expect? There weren't exactly SSDs in 2001.
Welcome to the future, guys. It's awesome, and it already happened a few years ago while you were busy protesting that you wanted no part of it.
And it's not just games that aren't supported. Lots of new hardware doesn't work fully/at all on older OSes at this point. There just aren't drivers or OS-level support for things that didn't exist yet when XP was released. You can use an SSD in XP, but you don't get TRIM, which kind of sucks. You get a hack/workaround instead that isn't as effective, but what do you expect? There weren't exactly SSDs in 2001.
Welcome to the future, guys. It's awesome, and it already happened a few years ago while you were busy protesting that you wanted no part of it.