is Vote to Close as Off-Topic an appropriate remedy for dealing with questions that are deemed too "populist"?
with due apologies, yes.
And, with due apologies, inflammatory language like "too populist" sounds a whole lot like you don't understand the background, so let me fill you in.
I assume you're aware with the Hot Network Questions sidebar, which is (with a pretty complete certainty) where you found the question that sparked this. It's less clear whether you're aware of how questions are selected for it: the algorithm, detailed here, selects for questions with a large number of answers and a large number of votes, and that inevitably selects for lowest-common denominator junk-food questions that a broad audience can upvote (but not for the more valuable questions on the site).
More noxiously, however, the HNQ sidebar is subject to an extremely damaging feedback mechanism, which allows for runaway snowball effects fed by votes that come from outside of this site's community, without any particular frame for what counts as a quality question or answer on this site. (Even worse, if external visitors come in, they're welcome to upvote, but they can't downvote.) This leads to a skewing effect that can take what would otherwise be a run-of-the-mill question, blast off all of this site's regular quality-control mechanisms, and award huge scores to questions and answers that would otherwise be considered mediocre or outright bad.
(And lest you think that this is just my opinion: here's some examples from Interpersonal Skills, Skeptics, Academia, Worldbuilding, Electrical Engineering, (then) Programmers and Code Golf complaining about the feature. There's plenty more where those came from, though there's plenty of relevant posts (particularly for the bulk of the complaints in chat) that are relatively hard to query for.)
Because of these problems, there has been a sustained series of petitions over the past ~ four years to reform the HNQ sidebar, so that it stops doing damage to SE sites and actually works to promote quality content. (My main posts on the subject are here, here and here, if you're interested.) To be clear: there have been multiple, repeated calls on SE to allow communities to moderate what gets shown on that sidebar and control how the titles there represent their sites, to curb the feedback mechanisms that make it harmful, and to reform it into something that puts the spotlight on quality content instead of lowest-common-denominator junk-food questions that alienate the users that communities want to keep. (Have a look through the hot-questions tag on Meta SE for a sampling.) Unfortunately, because of a variety of reasons, none of that ever happened.
... until, that is, all hell broke loose a month ago, in an episode documented in all its gory details (though not necessarily in easy-to-parse chronological order) at Revisiting the "Hot Network Questions" feature, what are our shared goals for having it?. It appears that SE is on the road to fixing this mechanism, hopefully by both reforming it so it's biased towards quality content instead of junk-food questions, and by allowing SE communities better and more fine-grained control over what gets advertised network-wide. However, there is no set timeline for this and the solutions won't come quick.
So, when a borderline-off-topic question with a catchy clickbait title gets picked up by the algorithm and starts picking up a snowball of votes from a population of users that have no involvement with this site, the toolset that SE puts at our disposal is essentially limited to one option: to slam the brakes on it. This involves putting it on hold, getting OP to fix the glaring problems (and then, if they're not responsive, doing more major edits that deviate from the OP's intent), fixing the title so that it's no longer a clickbait fly-magnet, and dealing with the inevitable crop of awful answers that generally crop up. Then, once the timer has cooled down, and if the problems have been fixed, it can be reopened.
Does that stub a few toes that ideally shouldn't be? Yes, it does. But until SE comes up with better tools to moderate this, the only tool available is to apply a more stringent topicality filter to questions on the list. If you want to change things, join the discussion over on Meta SE and help us pressure SE to fix this mess.
Some final notes regarding some additional inflammatory language like "abuse of reputation" and "authority" - you seem to have missed an important part of the "vote to close" mechanism, namely the vote part. Questions only get closed if five 3k+ users vote to close them, and if that quorum for a consensus doesn't get reached, single close-votes don't do anything to the question. Your problem here isn't with single users, it's with the quorum of (now seven) users who think this question should be closed in its current state and position.
is there a redress process better than going to meta and saying "hey what gives"?
This is precisely what meta is for. Why do you want something "better"?