I programmed a little bit in Autolisp (lisp dialect for AutoCAD scripting) as amateur and what I liked about it is that everything works the same way (even if you don't know all functions is not a big deal), it's just a list. JavaScript looks like a mixture of paradigms and syntax, trying to please everybody. When I don't program in it often I forget most of the stuff. Probably it needs to be like this but it doesn't look like an optimal solution.
I'd say on the power spectrum of programming languages, ruby is MORE powerful than swift.
There are so many things you can do in ruby that you can't do in swift, especially along the lines of reflection. The only stuff swift has that ruby doesn't comes in way of restrictions eg. typing.
If this was the main and only reason such that removing this limit Apple would have used Ruby, then why in your opinion didn't Apple try to implement themself something like RubyMotion (which was made by a company a thousands orders of magnitute smaller)?
Doesn't prove anything about Ruby's suitability, though.
I presume you haven't programmed lisp, because although there is very little syntax to memorize, there are a huge number of functions.