Absolutely this. The first sentence. Part of the problem is the vast echo chamber of Stack Overflow, where every JS question gets a jQuery/Express answer, even when the asker explicitly asks for vanilla JS help. Having hired developers in the past, this is probably my biggest pet peeve about web developer culture: Everyone seems to start from the top and only maybe work their way down through jQuery to vanilla JS. One of the questions I used to ask in interviews was to do some simple DOM manipulations without a library. This is a kind of fizzbuzz, as I'd guess probably 80% of the interviewees could not perform such basic JS functions as DOM element selection, which boggles the mind (even considering that the primary function of jQuery is its selector functionality). Certainly this experience has completely validated every claim I've ever heard about most developers not being hackers. As someone who yearns to learn in the most hardcore way (e.g. reading language references at the beach), I cannot fathom how so many people interested in writing code do not also possess the drive to tinker with (or at least wonder about) the inner workings of their tools.
Those reading specs interview those who say specs are irrelevant (same applies to basic (and advanced) math, seemingly) -- is not that satisfying, after all? ;)