>>(And I think Nokia and Apple hold top place for ditching technologies just as developers get to grips with them.)
Not sure what you're referring to. Apple used its original Pascal-based APIs from 1984 to 2000 and then switched to the current Cocoa/Obj-C stuff in 2000 and has been using that for the last 14 years. They also provided a relatively smooth transition path between the two in the form of Carbon.
Also I'll point out that writing software for iOS is literally the same as OS X except for the UI stuff.
Apple basically started at the point that Microsoft is struggling to get to 7 years later.