Maybe it's great for learning, but many of us wish to deliver a useful project and not just do something for purely didactic purposes

Which would be fine if the creators didn’t also push for Elm to be used for production use, which is clearly a dubious proposition.

This has been discussed to death, I feel.

People building their apps on a discouraged "leaked" implementation detail (JS native/kernel modules) got cut off from using it.

The reason for disallowing that implementation detail wasn't "hey, somebody is using it, let's teach them a lesson" but, as far as I've heard, improvements to dead code elimination.

You can (and people, me included, do) use Elm in production peacefully. Huge apps, nontrivial JavaScript interop needed. You can do all that without depending on JS native modules.

I feel like whether you use a (discouraged) implementation detail of the language is a good indicator of whether you'll have a bad time later on when that implementation detail changes ¯\_(ツ)_/¯