The react ecosystem is massive, and includes impressive projects like the various backends/renderers: react-native, react-sketch.app, react-vr, react-pdf, ink, that have no equivalent in other frameworks (or at least to nowhere near the same level of maturity), so yeah people ditching it may well regret it.
The 'native' stuff in your comment I don't agree with. You want browsers to start implementing native Android ListViews/Buttons etc? Browsers have a hard enough time implementing web standards.
BS 3 is still very valuable for responsive-site conventions within a team, especially if you use it 'properly' from Sass or LESS source. The main part looking dated at this point is the JS that still relies on jQuery. There're projects like boostrap.native [1] and e.g. ReactBootstrap to deal with that tho.
I'm in no hurry for BS 4 until IE (< Edge) completely dies.
> The plugin interface is a public interface too, right?
It didn't say 'plugin interface'. It said 'internal changes' that could affect some plugins. The way I read that is some plugins could be relying on internals (that they technically shouldn't, they may have good reason ofc).
> From the list of JS libraries they're using alone, I'm guessing it's going to get even fatter and laggier than it already was :(
Why? Only 3 of the 'JS libraries' listed are actual run-time code (React, Redux, Immutable). And React + Immutable are typically paired together specifically for speed optimisation reasons.
> I just want a listview of requests that appears in under a second
I think calling it a listview is a little unfair, and clearly there has to be tool/library cohesion with the rest of the Firefox devtools too, which are also much more than the odd listview.
