In reply to mark k..

the original point of the whole discussion which was about mimicking PHP APIs for translation, hooks etc in the JS world was very fast highjacked to serve as a platform for frameworks wars, without even giving a lip service to the original goal

This is definitely not the case. We had several weeks of meetings where we discussed this, and pretty uncontroversially decided we wanted them. The discussion has since moved on, because we made decisions.

Isn’t it bad enough to have the backbone framework in core? why do we need two frameworks? why can’t wordpress just solve the problems associated with backbone instead?

By doing so, we end up with our own bespoke JavaScript framework that someone has to maintain. We don’t have a great history of this; for a while, the media library was completely unmaintained because no one understood it. We’re much better off picking a stable, well-maintained, well-used framework with good documentation and established learning paths, rather than trying to invent this ourselves.

In addition, plugins and themes have the ability to use it themselves as well if they choose, which would be much harder if we invented our own framework.