Also to be fair, learning how to select elements by CSS class is so trivial that it doesn't effectively separate levels of developers. Whether you choose the basic JavaScript version or one from a popular framework, it should take less than a minute to look up if you don't already know it. I imagine that seasoned developers (and possibly recent CS grads, depending on school) are much, much less likely to waste time wondering why $(".myClass") is giving them a "$ is undefined" error in their Angular/React/etc... project.

I might be wrong, I don't have any direct experience with boot camps, but stripping dev skills down to just the minimal, core, practical skills needed to build a working prototype in the language-of-the-month seems like just the latest version of the same short-sightedness that has been plaguing businesses for years. Low-risk, long-term success will always come from building on experience, not "hacks" and short cuts. There will be exceptions/outliers, but they're just lucky, not a model to be copied.