I don't know we're you're getting those numbers - angular is 36k minified, backbone is ~10, and includes much less code (no rendering/binding library etc). Still a nontrivial distance, but a far cry from 700kb/10x
Continuing this point, Backbone requires rendering, binding, and probably relational models libraries. Not to mention the boilerplate and configuration code you have to write to tie all those libraries together. Less may end up being more.
Another point is that with all those libraries, how do you sanely manage the security and quality of your application? With the exception of just a few - almost every Backbone add-on library I've tried is badly programmed (un-SOLID / weird JS / no tests), not documented enough, and unmaintained solo-projects that just so happen to be on GitHub.
Another point is that with all those libraries, how do you sanely manage the security and quality of your application? With the exception of just a few - almost every Backbone add-on library I've tried is badly programmed (un-SOLID / weird JS / no tests), not documented enough, and unmaintained solo-projects that just so happen to be on GitHub.