That's incredibly high praise for Clojurescript. It's got some great features but it has flaws, too. I feel like many people new to web dev would be more confused setting up a Clojurescript project than they would be with JS. It was a lot of googling when I did it a couple weeks ago, and that's coming from someone who has done several times over the years (what's this boot thing, I was told lein was the best thing ever?).

Those are all great languages. It is important to realize that they will increase bundle sizes, which is a common rant about web pages these days. Hello world in Bucklescript/Reason, for example, is 23 KB (anything touching the std lib at least), Elm much bigger than that. My friend's 500 line Clojurescript/Reagant app was over 500 KB uncompressed, 5k lines of JS will come in at 140 KB.

It's worth being aware of the tradeoffs you are making, because often when people are selling new tech they tend to overstate advantages and understate disadvantages.