Technically impressive, I'm sure, but will it be around for another 30 years?
If someone writes a module using this, will I be able to rely on that module keeping on working for the years to come?
There can be a backend that generates Emacs Lisp code. Not necessary optimized or idiomatic, but it could be a good starting point for rewriting.
But in general, I agree with you.
I'm far from a JS fanboy but I think your point lends credence to the idea of using JS more than it strengthens the use of Emacs Lisp.
Similarly, the package repository is not exactly inspiring. Similar patterns of many packages doing the same thing. Often not bringing new advantages to the table, so much as revising old weaknesses. Many rooted in choice of language.
Which is actually not too complain of JavaScript. I do like it. And I love that people are empowered to try things. Even if they were previously done. I do wish people knew more options, though. Including myself.
But the way I see it, JavaScript is like today's BASIC. In a very fragmented computer market, it seemed like BASIC was the one thing that ran common between a lot of home computers in the 80s. While it's not a perfect parallel, it seems with all of the different platforms that are around today it's hard to find a consumer platform that doesn't have a JavaScript interpreter jammed in it, be it an iPhone or a ChromeCast.
BASIC wasn't all sunshine and rainbows either, but it was more than enough to help unify a fragmented world. I think JavaScript is very similar in that respect, and when the dust starts to settle on modern JavaScript it will be closer to accomplishing that goal.
Whether or not NPM is actually so impressive though, I won't debate. It's useful, but uhh... yeah. The baseline quality is not quite near something like, say, PyPI.
Still, I think you're looking at this from a different angle than I am. I haven't seen one person suggest that it would be a good idea to take the Lisp out of Emacs; simply that having the option to script it with other languages would be nice.
On .NET, UWP and Microsoft Office macros. It even is supported by .NET Native compiler, something that F# is still WIP.
And yes, at enterprise level, there are new lines of VB.NET and VBA being written every day.
But that's kind of beside the point, VB.net is nothing like the BASIC of the 80's or the 90's, it's got more in common with java.
The medicine you might take, has been probably measured DRC reaction curves in some VB.NET application.
It is the surviving BASIC, the evolution of QuickBasic and Visual Basic into the .NET environment.
Regarding the 80's BASIC, GW-BASIC was probably the last one of such type of unstructured line numbered BASIC.
That is the tool that many researchers with some programming skills reach for, maybe they will some day move to Python or R, but VB is what they use currently.