Ironically we typically spend less than 5% of a workshop talking about the router. So saying that we make breaking changes to sell tickets to our workshops is just naive. I can see how that's a gut reaction though, so no judgement on my end.
The react ecosystem does move really quickly. I think what's important to realize is that even though it moves quickly, if you learn the correct principles you'll just be stuck with minor API changes rather than architectural changes - which is a huge difference. I tried to approach the course from this point of view as well. Even if the API changes a little bit, the overarching methodology of building your UI will be the same. Someone who did the amazingly was Dan Abramov in is egghead series. Learn concepts, not libraries.
There wasn't a frustration with Firebase and React. It was a frustration with Firebase and vanilla flux. Firebase is essentially a store. So using vanilla flux you end up just trying to keep your store in sync with Firebase.
I know I'm a little biased since I wrote the library, but we use Firebase in production and it works just fine for us. Auth, real time, scalability, and security out of the box is why I love Firebase. Not saying any other option is bad, I've just had plenty of success with Firebase.
Very interesting idea. I think where this breaks down is the fact that you can learn a lot from reading/studying outside of work. A person who spends all their spare time studying and doing side projects shouldn't be held to the same restrictions as someone who just learns at work.