I wouldn't recommend a heavy framework that tries to magicfy everything for you, that kind of framework is really not to my taste. ie emberjs. But backbone itself is very light, you can probably read the entire source in under 30 minutes. Nobody is telling you to pack some huge framework on top of backbone, but depending on the complexity of your application Backbone might just not do enough.
This is why I really like backbone, because you have the option of going big or small on the libraries you're using depending on your needs, and each individual component is small and easy to understand.
Something like https://github.com/marionettejs/backbone.marionette is just another toolbox where you can pick and choose the tools you need.
This is why I really like backbone, because you have the option of going big or small on the libraries you're using depending on your needs, and each individual component is small and easy to understand.