> Stay away.

Yep, stay away from the advice of some systems programmer who "follows" web development and feels entitled to comment on thing he knows very little about.

Backbone is not MVC framework, it does not have Controllers. The name is very apt: it is basically a small skeleton for your app which gives you things you'd have to reinvent and provides some organization and structure.

Actually, the description on backbonejs.org describes it very well:

  > Backbone.js gives structure to web applications by providing models with
  > key-value binding and custom events, collections with a rich API of enumerable
  > functions, views with declarative event handling, and connects it all to your
  > existing API over a RESTful JSON interface.

It is very small and simple (and even "rich API of enumerable functions" is provided by underscore.js on which backbone.js depends).