Just a quick glance at this - are they essentially js portlets?
I think this comment best describes the focus: https://news.ycombinator.com/item?id=7429659
I'm hopeful that BRJS will have wider applicability since Blades are conceptually similar to Web Components and I'm sure the hope is that they are widely usable.
We'll see!
However, Web Components won't remove the need for a service layer which is also provided by the default BRJS runtime or the encapsulation of tests, i18n, config and other resources within a Blade.
Demonstrating how to use BRJS with Web Components (Polymer) is most definitely on our TODO list.