BTW Sacha, thanks so much for Discover Meteor, it was what I cut my web dev teeth on! Somehow I hadn't heard about Vulcan until now. It looks really interesting and I'll be looking into it more.
It's a missed opportunity, but the mistake was the Meteor Development Group's in betting on the JS community being satisfied with an "opinionated curation of the stack". The JS community has the attention span of rabid squirrel, and this was obvious back in the 0.8 days. They were never going to love a single bundle of choices for long.
How many other JS build tools & frameworks from 2014 can say the same?
It's on Meteor 1.6 now, and you'd be mistaken about "much changes". Blaze to React was a nearly a rewrite; Atmosphere packages to npm was a significant change for the internal dependencies we developed; removing the custom file loader itself that preceded Atmosphere packages meant touching every single file.
The original code might have still worked, but the code would be helplessly outdated and stuck on a dying platform's technologies. As it is, though, the extensive and continuing effort to update the code means that now, we have a React/node app with an idiosyncratic webchannel connection to Mongo and a build process that's outdated but manageable, and still under active development of new features.
I credit the Meteor Development Group with recognizing that the stack they wanted to lock people in on, wasn't going to work (Blaze, Atmosphere, Mongo) and providing a paced transition off those pieces early on. But if we hadn't kept pace, we'd have a half million LOC app that would be termed "legacy".
We made the same transition, but just replacing one package/ui part at a time when it suited us, so we always kept releasing new features each sprint while gradually modernizing our code base.
Build tools wise, a simple Webpack/Babel config from 2014 would be relatively straightforward to update to the latest versions.
On the 60% line
Also surprised to see ClojureScript's satisfaction rate at 60%. In the past year or two it's become much easier to use NPM packages, which was IMO the last remaining huge missing piece. It's now a great language for web development, providing what JS couldn't: a rich standard library with, ahem, consistent API's, a strong FP flair with excellent immutable data structures built in, and maybe most critically of all, a somewhat constrained macro system that allows users to write and distribute third-party libraries for syntax that in other languages would have required an extension of the language standard.
All of that is (I think) desirable by anyone unless you're hardcore anti-FP (with the one exception, I guess, that macros can be and are abused, though I haven't seen it very often in the CLJS ecosystem). So why hasn't ClojureScript seen more adoption? It's the age-old curse of Lisp, I guess: those dang old parentheses which decades of CS curricula taught in ALGOL descendents have rendered foreign and horrifying.