The idea of a programmer learning on a language and then being "locked in" doesn't really make any sense: I have no love of Apple, and I have nothing but the most cynical thoughts regarding Apple's position with clang, LLVM, and Swift, but I have absolutely no fear that someone who learns to program in Swift could ever be "locked in". I learned to program in languages like Logo and BASIC. I then programmed in TI-BASIC for years and later Visual Basic. I do not consider any of this a waste of time, and none of he knowledge I learned of software development was somehow locked in to any of these languages.