How about opening Swift compiler source code (and porting it to other platforms?)
And, what are the OS requirements for xcode 6.3? Is it possible to install it to old macosx system (snow leopard, for example)?
Sorry, talks about "designed to lock in" is a non-falsifiable theory. If you wanted to build a language for the future and even make it open once it's tested and polished, you would do the same thing: gather a small team to work privately without distractions, make it grow in a controlled environment (so you can safely make breaking changes fixable with some migration tools) and when it's mature enough, release it wide open.
I think there's a practical reason for Apple not to lock-in using a programming language. Proprietary tools limit amount of talent being provided to the platform. Really smart brains would spend time either in suboptimal open platforms or choose some other garden (e.g. .NET, Java). It's one thing to lock in consumers into an ecosystem, it's another to detract smart developers by threatening them with lock in.
Swift library is Cocoa and even if they eventually open Swift, it is going to be as useful as Objective-C is outside Mac OS X and iOS.
Personally I don't care. What I care is about tools that make my customers happy.
A Swift compiler without the Mac library will be a very poor choice in regards to any existing ML language.
So, I think it's more complex than you're admitting.
Garbage patents stabbing the software industry in the back yet again.
First I've heard of this. Glad there was actually reasoning behind not making it open as promising that and then going back on it without telling anyone why was very strange.
The only reason I can see to not open it up at the moment is that they're not ready for it yet. I reckon it'll come soon enough.
Which is a shame because OSX 10.6.8 was the most stable, zippiest performance OSX ever and still had the nice virtual desktop. Sadly I lament the old virtual desktop. I'd still be on it if I could be.