I actually know the engineer who used to be responsible for porting some of the technologies you're talking about to non-Apple platforms. According to this per

I actually know the engineer who used to be responsible for porting some of the technologies you're talking about to non-Apple platforms. According to this person, the barrier is not some strategic lock-in plan at Apple. The barrier is more about business incompatibilities. For example. It's fully possible for Apple to ship an iCloud SDK for Windows. But the way iCloud works is, it's integrated deeply with each application. It is believable that your average iOS app, or your average Mac app, would be willing to integrate with iCloud's SDK. But is it believable that your average Windows app will? Will Microsoft do the work to integrate the iCloud SDK with Office on Windows? Of course not! The idea is preposterous. Far more likely is that Microsoft's own SkyDrive or will become standard on Windows, or maybe Dropbox will, which is designed in such a way that it doesn't have to integrate with anybody's product. Apple could have designed iCloud in a way that didn't require third-party support, and maybe they should've, but they didn't. And anyway that would be a completely different thing than the way iCloud is used right now. Apple has the willingness, particularly post-Jobs, to license some things to other platforms. Especially if it grows their own ecosystem, and a lot of Apple's stack falls into that category. But getting the deal done has more ingredients than just Apple being willing and some end-user who wants it. You can't say, merely because there is no technical barrier, that clearly every time an Android user buys a book from Kindle instead of the iBookstore that Tim Cook cackles with glee. I pretty much guarantee he'd be interested in getting a deal done on that.