A bit of a hater comment incoming:
On a more general note, I never did have anything against Ruby in general, let’s make that clear from the start. I liked working with it for quick scripting, actually a lot. I can see why Mac’s Homebrew is written in Ruby.
That being said, Matsumoto in general has been very disconnected with the real world programming. I watched many interviews and he always struck me as a shy guy writing manga slash-fiction for middle-schoolers. Kill me if you must but I trust in my experience with people. He’s one of these people that “plays with technology” and then people get crazy about what he invented. One of the people who’ll naively tell you “just follow your dreams, it’s that simple!” (while likely not having to think about bills and college funds 
).
It took him like 10 years to admit that having first-class baked-in parallelism and concurrency that are painless and less likely for the devs to shoot themselves in the foot with, is a good thing to have. WTF? How is this guy’s opinion on technology relevant at all? Why should he be listened to? He’s not living here on Earth where we must work for money and maintain projects for years, that’s for damn sure. He’s likely handed money because of his reputation. In the evolutionary sense, his thinking likely stagnated in his privileged positive bubble.
I moved on from Ruby (mostly from Rails though) for good 5 years now and my opinion on the topic is likely worth nothing but then again, time and distance give you perspective which IMO shouldn’t be ignored either.
So here it comes:
Ruby is worthless apart from being a very nice scripting language. It’s NOT suited for web apps (yes, even with Rails in the picture) and it’s NOT suited for any data science or algorithm coding as well.
I’d only use Ruby just as far as not having to use bash/zsh for scripting.
Sorry if this is too negative but I had to get it off my chest. Strong personal opinion that need not be respected: Ruby should just be forgotten. 
They can try hard emulating actors and JIT but it’s a waste of energy and a fanboyism taken to the extreme where people just forget that other technologies exist.