That last part's been true for a lot of people. I don't know if Elm will see the same massive success, but when I compare what it felt like to discover Elm vs. what it felt like to discover Rails, I see a lot of similarities. First, both Elm and Rails represent very curated experiences with a very strong emphasis on being enjoyable to use. Second, that curation involved deep thinking, in each case, about the best way for the framework to do its job, which thinking came in each case to idiosyncratic and (in my opinion) superior conclusions.
Third, they both showed up in very similar environments. Rails had two main sources of competition: an over-ambitious, platform-y technology which was painfully boring and tedious to work with, and an overly simple alternative which encouraged you to write very hacky code once your project grew beyond a certain size. Angular 2 would be the equivalent to J2EE in this analogy, and obviously React, as a view-only technology which intermeshes presentation markup with application logic, would be the PHP.
OK, I apologize. I know Angular intermeshes markup and logic too, and I know both have insane ambitions of being platform-agnostic mega-/meta-frameworks, and indeed, Elm itself has you write your HTML as Elm functions, so it too blurs the line between logic and markup somewhat. But I needed a J2EE and a PHP, and Angular is definitely the over-engineered one.
Only time will tell if these two analogies hold, and indeed I'm a lot more confident in the Angular snark than the React snark. I could be wrong about both. I built a toy recently with React and enjoyed it a lot (but then again, PHP makes a ton of sense for really simple barely-dynamic pages). And certainly, Evan Czaplicki doesn't seem like a DHH to me at all, although I could totally see him as a Matz.
Still, one of the weirdest aspects of Rails's success has been a particular contrast: everybody steals ideas and vocabularies from Rails, but virtually no other project has said, "yes, Rails is right, programmer happiness should be a top priority." You can find migrations, REPLs, code generation, and "REST means CRUD" in every language now, but you won't find "programmer happiness is the top priority" in many other places.
I think this is partly because a lot of the old blog posts where DHH praised and imitated Kathy Sierra have vanished, so nobody remembers that making users happy is about making them awesome, and a framework which makes its users awesome is doing what a framework should do. It could be that the "look at me, I'm awesome!" vibe of early Rails devs was hard to take, so nobody did any serious thinking about it. It might even just be because it's hard for anybody to take DHH seriously in the first place when he has such an egregious straw man problem.
However, one way or another, DHH told everybody that programmer happiness is the secret to Rails's success, and everybody gathered around wondering "what's the secret to Rails's success?" and virtually nobody ever considered the possibility that when DHH said it was programmer happiness, he was telling the truth. And this confused me, and it continued to confuse me for a full decade, and then I found Elm.
I have absolutely no idea if Elm's focus on being fun to use comes from any awareness of Rails at all. But Elm's designed to be fun to use, and, as a consequence, it's fun to use. What a shock! And as it turns out, everything that makes Elm fun to use also makes it a good framework. It has a clean mental model. It doesn't throw mysterious, aggravating runtime errors. Its compiler errors are easy to understand, easy to correct, friendly, and so polite that its British users assume the language itself is British. It's fast as hell in development and production — pull up a Chrome timeline sometime and compare an Elm "hello world" with the festival of
document.writethat is an Om "hello world" — and it's basically awesome.
I think my new rule of thumb should be that all of my code should be fun to use. It worked for Rails, and it's working for Elm too.