First off, this is very well written. Secondly, I'd like to state that I think that Objective-C and Cocoa were really good. I disagree with most of the design p

First off, this is very well written. Secondly, I'd like to state that I think that Objective-C and Cocoa were really good. I disagree with most of the design paradigms today, but I think the Objective-C/Cocoa ecosystem represented something approaching a local maxima in the mutable programming space. Maybe not even a maxima, as I was actually really happy with the direction it was going pre-Swift (KVO was starting to get good in NSTreeNode, the language additions were welcome, etc.) All this to say: I think the Swift transition was really misguided, and I was incredibly surprised that that wasn't the general take at the time. Everything about it seemed not well-planned out: the fact that no one at Apple had heard of it (you have the world's best ObjC programmers in-house and don't bother to get internal buy-in first!), the fact that it was really a response to C++ not Objective-C (this is so clear when listening to Lattner, who incidentally, did most his programming in C++ it seems), the fact that they sold it as good for everything from scripting to systems programming (huge red flag), and on and on. But the real concern here was the opportunity cost. What was the problem they were trying to solve with Swift? That square brackets were off-putting? That a group that until that point were totally bought into dynamic dispatch should switch gears completely to a strict typed language? If you ask me, the only goal that should have mattered was making development easier and expanding the scope of people that could approach the platform. And, for the record, I am sure they believe they attacked this problem, I clearly disagree however. I think the real areas ripe for improvement were the tools. Look no further than Facebook, with React Native and the no-recompile workflows where you change the UI and see it instantly on your device. This would have been game changers in making development easier, not adding Maybes (and this is coming from someone who does immutable development now). Objective-C could have been evolved into the language they wanted. It would have probably taken just as long as however long this "transition" is going to take, and it would have given everyone immediate actionable benefits instead of being a binary switch that comes along with the pain of having to ship the runtime. Instead, we have discussions about whether Foundation is going to be rewritten in Swift. This seems like such an incredible misprioritization. Essentially creating a situation for yourself where you have to burn everything down and start from scratch, all while in the meanwhile have the head-scratching platform where the base libraries are written in a dynamic language and user land code is a strict systems language. The last thing I'll mention is the worrying lack of "purpose" for Swift. Talk to a Rust guy, and he WILL tell you the reason to use Rust. Talk to a Haskell person and they'll do the same. The sole reason for Swift seems to be "to take over the world". It is decidedly not a very opinionated language in that regard. In the ATP interview, Lattner even said that dynamic dispatch may be added later to Swift so no one should worry about it, it seems like such a kitchen sink. (I loved the bit where he said that if they add in multiline string literals they can probably "win" the scripting space). Not a lot of passion there.