Look, I wrote one of the only published books on Backbone, and it will always have a special place in my heart, but ... the OP has no idea what he is talking about.
Backbone employed a two-way data binding flow. You're responsible for updating the models (ie. state) (way #1) when the user triggers events, AND you are responsible for updating the DOM whenever the models (ie. state) changes (way #2).
In React, they used a revolutionary new paradigm (flux), making it so you only worry about one direction (updating the models/state in response to events); you never render anything (React renders everything for you in response to state changes)!
If you've tried developing a non-trivial site with both, it quickly becomes apparent how much that one difference completely simplifies a huge aspect of development.
This is off topic but I need to ask you to stop breaking the site guidelines. You've been doing it repeatedly lately (not in the current case—present comment is fine), and we end up banning such accounts.
Backbone employed a two-way data binding flow. You're responsible for updating the models (ie. state) (way #1) when the user triggers events, AND you are responsible for updating the DOM whenever the models (ie. state) changes (way #2).
In React, they used a revolutionary new paradigm (flux), making it so you only worry about one direction (updating the models/state in response to events); you never render anything (React renders everything for you in response to state changes)!
If you've tried developing a non-trivial site with both, it quickly becomes apparent how much that one difference completely simplifies a huge aspect of development.