To run? Absolutely not.
Edit: Looking up the quote it seems to just be the person being pedantic in how they define operating systems.
I disagree though. While there are benefits to that approach, I feel like language innovation would be stifled to a certain degree.
I'm not sure I completely understand which part you find backwards. Do you mean merging language runtimes and the OS is a bad idea, or that you think merging them would lead to more innovation?
I can see an argument for both (in terms of innovation), but being able to run only one language environment on a computer at a given time would make it much harder and heavy weight to use new languages. Or at the very least, new language runtimes.
What a surprise
Pragmatism beats idealism in the real world