You're right, I'm shooting my mouth off here, but this is the whole problem with these huge frameworks: they're so huge that, by the time you've spent the time to evaluate them properly, your objectivity is likely to be compromised. You'll never see an even handed comparison between the two.

This isn't unique to js frameworks. There's plenty of systems like this e.g. Hibernate. At least backbone was small enough that I could seriously evaluate it in a month long project. (For the record, I didn't like it, but at least I actually can have a considered opinion on it without being well past the point of no return.)