Scott I definitely see what you're saying. I guess I'm a little impatient/ADD when it comes to wanting to modify component internals.
If there's something simple missing from a component, I want to just stick a property on the consumer and 'bam' there it is, instead of having to potentially clone, update, pull request, etc.
But on a philosophical note, it seems like theres potentially a lot of boilerplate that could develop, as often times we're just exposing properties and mapping them right back onto the inner element in question. The inner element then becomes full of bindings. By having some kind of external addressing mechanism, we could eliminate that boilerplate and keep the inner implementation cleaner.