I think that Hiccup's idea of writing the tree as a tree-like data structure is superior to writing a tree of function calls.
I tried doing something similar in JavaScript; the result looks a bit silly (I realized the elegance of not needing to delimit lists with a , in LISP right here) and has questionable performance: https://github.com/Lokeh/hux
In fact I'd argue the value proposition of JSX is already relatively low when you factor in hyperscript in regular javascript (and yes there are component-compatible hyperscript helpers for React).