[carapace]

Serious question: What's the business value case for not using Elm?

[vages]

Network effects: The sufficiently large pool of competent programmers who already know Javascript makes it easier to hire people. The many people you don't hire often make some of their work available for reuse for free.

[Guthur]

It's also possible that you can move faster with a dynamically type checked language.

I would be of the opinion that it is faster because if static compilation was a free lunch there would be no question

[kod]

If static compilation was a free lunch AND people were rational, which they are not, there would be no question.

I definitely move faster in decent statically typed languages, but I did invest time in learning.

[jxxcarlson]

Yes, move faster, then pay the price later when stuff is broken and hard to fix.

[vogre]

If you doubt that it will persist in 5 years, and want you app to be supported in this timespan. Nothing is worse than abandoned technology in the core of your application

[boubiyeah]

You would have to bet on Elm being maintained in the future. It's quite a lot of buy in, especially considering it's just one guy.

Also, some apps are just very difficult to code in Elm (interactive, lots of DOM manipulations, video, etc) and it's just not worth it.