Unless you fundamentally disagree with having paid updates for OS X (which is fair enough if a little at odds with Apple's business model), then, well, it naturally follows that Apple are going to add new features to OS X now and then which they won't (can't) backport to earlier versions - and not just stuff that makes an obvious difference to end users, but also stuff that makes programmes easier to write. If they take advantage of those features then the apps won't run on earlier versions of the OS. It's really quite simple, and I think it's unfair to call it 'forced obsolescence'. The software wouldn't be written without the frameworks, and if the frameworks aren't updated, well, then nothing new would be added to them...