I find Elm exciting, and with the prevalence of React/Redux these days, a lot of front end developers would be wise to familiarize themselves with the origin of many of the concepts borrowed from Elm.
It drives me crazy that Microsoft doesn't push it harder from an investment perspective. They don't even write books about it :)
I've been meaning to try Elm since I've been playing around with Haskell more and more. Purescript is relatively similar but allows you to build more than frontends. It seems Elm has grown quite a lot in popularity though.
The only problem from my experience trying to use it in a project is that since it's alpha software a) it's changing so fast that APIs/libraries are very unstable to the point they are almost unusable if you try to follow newish releases (this was 6-8 months ago, I hope/expect stability has improved) and b) you have to be intimately familiar with Haskell.
As the OP's article describes about Haskell with PureScript the documentation situation is even worse, the documentation is 90% "hard" and 10% "soft". Which is fine if you know Haskell, or even a bit of Elm, but it's very tough coming in as a newbie of both Haskell and PS.
Monads then seemed much easier to understand after Elm and reading this: http://adit.io/posts/2013-04-17-functors,_applicatives,_and_...
I always had a hard time wrapping my head around functional programming, but elm was easy to understand and shows off the strengths of a functional approach.
Here's an exciting example: https://github.com/dailydrip/firestorm
For other haskellers, Purescript seems to solve this problem.