Considering that Apple created Dylan I'd argue that they have all the "language skills" needed. But Dylan was a failure, in part because of politics, but also because most programmers are conservative (I'd say dumb code monkeys, but this isn't exactly true) and don't like their "new" languages and tools to be "too new".
Clojure is a really great language, solving real problems in a nice way. But in language popularity charts I just checked it's far beyond first 20 entries and close to Forth(!) on one side and Erlang in the other in popularity. Clojure (and Erlang, and Forth of course, but also Haskell, OCaml, F#, Smalltalk and Io and many more) is just too new, too unfamiliar, too intimidating for our conservative programmers to consider using. And for Apple that was probably the reason for rolling out a somewhat "normal" language instead of something really good.
For mainstream programmers they are, in that they have features they never saw before. You know, like in "it's something new for me" or something like that.
The fact that objectively some of those languages come from '50s and '60s (like Lisp in '56 and ML in '63 IIRC), which makes them ancient by today's standards, doesn't matter. It's really sad. I devoted a couple of years to learning about and trying to use such languages (see here[1] if you want) but I'm in a very small minority; most young programmers never use anything other than 1-3 core languages they learned; the number of known languages increases with years of experience, but it's still biased towards currently mainstream languages. Which are mostly crap.
Anyway, that's how it is: most programmers are very conservative in their choice of tools they use and feel no need to look for alternative tools to use.
I don't want to spend too much time discussing this, but I read Swift guide[1] and even played with it in Playground, and I'm 97% sure that every single Swift feature is borrowed from currently mainstream languages.
There's a difference between "oh, it's like feature X in C#" and "well, didn't Common Lisp implement Y 30 years ago?". Feature X will be perceived as nothing new, merely catching up; Y will be seen as new, dangerous, cryptic and best avoided. I think Swift designers intentionally packed their language with Xes and added almost no Ys, exactly because they didn't want it to seem as "too new, esoteric, unproven" and so on so forth. This is a sane business decision, by the way, I just happen to dislike it.
Clojure is a really great language, solving real problems in a nice way. But in language popularity charts I just checked it's far beyond first 20 entries and close to Forth(!) on one side and Erlang in the other in popularity. Clojure (and Erlang, and Forth of course, but also Haskell, OCaml, F#, Smalltalk and Io and many more) is just too new, too unfamiliar, too intimidating for our conservative programmers to consider using. And for Apple that was probably the reason for rolling out a somewhat "normal" language instead of something really good.