I've clarified at the bottom of the post that JavaScript is probably going to get some of these features in the future. One of the points I was trying to make was Dart has these features now (and because Dart compiles to JS, it means I can deploy these features now).

The other question we should ask is, why didn't the original author use those new shiny JS features in his app? He's a crazy smart developer. My hypothesis: because the out-of-the-box dev experience doesn't include modules, promises, etc, there's a higher barrier to using the new shiny JS features because the developer needs to first A) know about them B) find the right polyfill.

Thoughts?