Because Elms error messages were actually mind blowing. They fundamentally changed my view of what a language and compiler is capable of. It honestly makes every other language laughable.

I seriously want anyone who ever designs a language to spend even one weekend playing with Elm just to see what's possible, because prior to that I would have never even considered a compiler could be so helpful. At times it was so clear and accurate it seems like it could've just fixed my code for me.