Ok, I think I understand. But as long as the MS OS updates are backwards compatible in a sense, then we're good. In other words, if I want the latest Skype version and it requires Anniversary, then that's fine as long as the other apps don't break.
It seems to me that this is just something we'll have to live with from now on and it's related to the MS statement that Windows is from now on more like a service. I took that to mean more frequent upgrades with medium amounts of new features but also with bug fixes and optimizations. So we're beyond buying WXP, then having to buy the new W7 for new features, then W8 etc. I actually think it's an improvement, although it places big demands on MS to keep the upgrades nice and functional.
Essentially the alternative is "freezing" at some level and then just output bug-fixes and security updates, whereas newer versions of software taking advantage of new features requires new large OS installs, probably for pay.