My favorite quote: "See, unlike in any other languages that consider themselves more "professional", you can do pretty bold shit in JavaScript and not be judged. This reduced cost of failure breeds innovation like nothing else. JavaScript community sips through more concepts and ideas in a year than Ruby/Rails did in it's entire life cycle."
(on Javascript) "And if you're wondering, yes, it is still a huge mess. Yes, it is still full of hipsters, like coding on a typewriter kind of hipsters. And, yes it is still the same single threaded nonsense."
Ruby like all languages has its down sides, which basically all revolve around lack of speed and proper parallelism, which last time I checked were both actively being addressed from different perspectives (http://jruby.org/bench9000/, https://github.com/grosser/parallel, Rubinius), but I agree that if you need those features now and in production, then you will start drowsing a bit.
Another big down side in Ruby from my point of view is a lack of a proper GUI toolkit. But, it's hard to be big in every side, without running in a browser being backed by a giant like Google (but Opal http://opalrb.org/ can help with that.. and I think that https://github.com/zach-capalbo/flammarion should deserve more attention).
To address those missing features in the meantime I've taught myself C#, which feels comfortable and solid. At the same time I had to do some works in Javascript and I got "shit done" too, but it would be stupid to deny that it was by far the least pleasant experience of the three.
Ruby, even though it's not good a choice for everything, gave a big heritage to the software development world, the concept that "developer happiness" can be accomplished (see how many languages Ruby inspired and how many frameworks Rails inspired) and this will never be forgotten just because JS or another language is running faster or because it's the browsers default, (though I reckon this is a big advantage).
And "developer happiness", is not as the author writes just "The idea that a developer should just kick back, relax and things will happen magically for them". Maybe that was a stereotypical thing at the beginning stages of Ruby on Rails, with the most popular case being the Rails "generators". But Ruby community has long got away from this paradigm. Real "developer happiness" it's a thing. Maybe for Ruby this vision didn't fully make it to the real world for the reasons at the top of this post, but sooner or later, with Ruby or some other language, it will.
Lastly, I predict that Microsoft will have a surprise on this thread, too.