I think Apple's only priority for Swift is to make sure future products using future versions of iOS and OSX are more attractive to buyers than other companies'

I think Apple's only priority for Swift is to make sure future products using future versions of iOS and OSX are more attractive to buyers than other companies' future products using future versions of Android and Windows. I think Apple is fine with the idea that the best way to target their legacy devices is with their legacy language. They're probably even okay with losing people who don't upgrade quickly as customers altogether. "Let the slow upgraders switch to Android and further fragment their market instead of ours," I can imagine them saying. I don't get the feeling that Apple is willing to sacrifice any future benefits (including simplicity) in order to improve legacy support. More than any other company I see, they want to encourage customers to abandon the past and buy something new. If Swift doesn't work very well on iOS 7, I can't imagine that ever changing except as a side effect of fixing something for iOS 8+. It's strategic focus, not incompetence.