I just had an interview where the company passed because they wanted someone with specific Javascript experience, and I had only useless unrelated experience with Lisp, C++, Java, and C#. None of those could possibly help a new hire be successful, when what they really need to know is the syntax of a specific scripting language.
There was the same problem with ActionScript back in the day. So many people had played with it in Flash, and were going for jobs developing RIAs. They had no idea about software development, but knew how to say goToAndPlay(1) and add a click handler.
We are seeing the exact same thing with JS. The more advanced frameworks tend to weed out those that are just playing around, from those who are serious software engineers.