Just the fact it uses Handlebars templates disqualifies it as a viable option for me. Handlebars is terrible to work with, especially once you're used to JSX type of options.

HBS = restrictive for nonsense reasons. The separations of Model, View, and Control really don't make sense anymore. It's outdated.

I've worked with it for years and I consider myself familiar with it up until 3 years ago, but I would never go back to EmberJS. And that's why the salaries are higher for Ember developers: they're rare.