Comment by machty

Because it's such a thin layer over JavaScript, you don't have to port/reimplment all the stuff that JavaScript has already solved to your templating language / abstraction of choice. I still prefer Handlebars, but JSX elegantly sidesteps lots of issues at the expense of not actually being real HTML and handling flow control stuff somewhat awkwardly, but you really gotta try it out to get a feel for the tradeoffs.