Why use Backbone.js?
backbonejs.org
backbonejs.org
It felt to me, in Ember, that I was creating arbitrary objects and attaching to arbitrary objects and from that arbitrariness instances were created...
Coming from the Backbone world where you create a definition and then initialize it manually, this was a very disconcerting change. Unlike the Backbone community, I was also unable to get any sort of help or direction after hitting up Twitter or IRC.
Support should not be underestimated.
1) Backbone gives you a handy way to interact with browsers and the DOM. It does not remove the necessity for you to interact with the browser.
2) It seems like a lot of folks get into trouble when talking about/thinking about event flows and using the abstract messaging layer that Backbone provides in Backbone.Event. Backbone gives some basic and handy defaults events for folks to use, but I always think it's worth considering which parts of your app talk to each other, and what that interface looks like.