His question takes away the people who are not interested. It's useful.
If this is a measure to eliminate candidates who are ultimately less interested in doing the work then so be it.
It was pretty clear in that the primary motivation was to eliminate candidates who either lack confidence or competence so that you can spend more quality time with those candidates who care more about the respective skills.
I don't know you, but I am guessing from your highly defensive tone that you likely fall into one of the categories I described in the previous paragraph. If this means of candidate elimination is emotionally offensive you should ask yourself why. When candidates exceed the number of openings somebody must be eliminated.
While someone must be eliminated, you need to ask yourself why you're selecting for those who would opt to work under random and arbitrary bullshit when they don't have to.
Unless the job description made clear why it wasn't available, I would take this as a sign of a toxic workplace and avoid it. It isn't about jQuery being banned, it is about the type of workplace where jQuery is not only banned, but such a ban is mentioned early in the interview process. I guess if you want people who are okay with such a workplace, then you are using an appropriate heuristic.
You avoided explaining this. If eliminating unnecessary abstraction is offensive to you then I would be more happy to eliminate you from employment consideration at the earliest possible moment so that I don't waste your time.
If the hiring individual dictates what trade offs are made so far in advance that it happens in the interview, it means they aren't just eliminating unnecessary abstractions. Premature optimization isn't generally a good thing. Premature optimization showing up in an interview as a way to get people to quit is even less likely to be a good thing.
Disrespect permeating the industry. A candidate is either a rock star 2% or worthless the rest. And everybody does successfully hires only rockstars. Mathematical paradox. Though seeing how you mention 10 years experience as something important I'd guess you're young, and that would explain your gimmicky and capricious approaches to candidates selecting and interviewing.
I am less interested in copy-paste coders.
When I have interviewed in the past I literally stopped reading once I see contact information and save reading it for during the interview. If the contact information is not the first thing on the resume it goes in the trash.
For valid heuristics I start by telling candidates something they don't want to hear. If that means they drop out then good riddance as I have 30 other people who are more interested in the position.
Examples:
* When I did this years ago I would email JavaScript candidates to set up an interview time and I would tell them jQuery isn't available in this job. Half would immediately drop out. Good.
* For modern JavaScript candidates tell them the DOM will feature heavily in the interview and there will be no MVC framework. Half will drop out.
* A rough equivalent for Java is Spring MVC or forcing architecture considerations.
You can filter people pretty fast just by focusing on foundational simple vanilla code questions. It is astonishing how many unqualified people apply for jobs whose resumes are a complete waste of paper.
The current employer would only take contractors for new hires (let agencies find the people) and would give out some interview questions to the contract agencies so that candidates knew what to study for before showing up for the interview. Even still only 9 out of 73 interviewed candidates were selected (who knows how many resumes were filtered out).