The fact that Dojo and YUI can be used like a framework (so can jQuery, with jQuery UI, etc) is not the point. The point is that, at the point-of-inclusion, tho

The fact that Dojo and YUI can be used like a framework (so can jQuery, with jQuery UI, etc) is not the point. The point is that, at the point-of-inclusion, those 3 tools/libraries are far less intrusive to the architecture of your site than including Backbone/Angular/Ember.