1. A lot of JavaScript frameworks are being released 2. JavaScript frameworks are being updated too fast.
His biggest example, the Angular 2.0 split, is of the second one, but he seems primarily concerned with the first one.
I can see the first one being a problem primarily for developers keeping their skills up to date. The fact is that once you've put a decent amount of code down into an application, you're not going to be constantly switching frameworks. Maybe do it once, but otherwise the applications that are already built will stay on a stable foundation. So for developers working on a single or stable set of applications (not client work), this shouldn't effect their actual work. There may be an issue of skill decay if employers are constantly looking for the latest and greatest, but outside the Silicon valley bubble, I still see a lot more jQuery and Backbone job postings than Ember or React.
As for the issue of frameworks lacking stability, I frankly don't see that. Yes Angular is making big breaking changes. But otherwise? Let's look at the other 6 biggest front end libraries/frameworks.
jQuery has been fairly stable for a few years now, with minimal breaking changes.
Underscore has been very stable, albeit growing with competition/help from Lo-Dash
Knockout and Backbone have evolved slowly while remaining small and very small respectively.
Ember has a very clear process for moving their framework while allowing actively developed applications to stay up to date in a reasonable way.
React is still pre 1.0 and that's something you should know going in.
Basically if you started a project with any of those technologies (or angular for that matter) at some point in the past 3 years, you've probably had a pretty easy time in adjusting as the library specific concepts have changed.
I just don't see the idea of "Frameworks are evolving too quickly" as being particularly compelling. There's a lot of information out there. Yes if you want to know it all and always be using the newest shiny thing, it will probably be too much. But none of this is preventing anyone from actually building useful things today.