In reply to KTS915.

WordPress has, over the last couple of years, been stuffed with unnecessary cruft

Having a much better external API is a great way to start avoiding this. Rather than rolling out more "cruft", features can be developed as completely external layers instead.

Take for example the Customiser, which some may call cruft. This could be built completely as an external application rather than being built into core.

That said, it could continue remaining part of core (and I hope and expect it will); just because we're adding technical abilities, doesn't necessarily mean things will change. The possibilities it opens up can certainly help here.