Of course it should be re-opened.
“This question cannot be answered as expected” is a good answer. The particular rendition of that sort of answer here isn’t just a good answer, but a great one. And most crucially, the fact that “this question cannot be answered as expected” is the right answer to the question does not, and never has, and never should, mean the question should be closed. The correct and valid state for some questions is open, but unanswered. Sometimes, as here, it is better still to answer explaining why that is the best result we can expect. And again, this case, the particular answer is a stellar example of that sort of thing.
Looking to the answers a question gets as a cause for closing it is dangerous, and should be done only with extreme reluctance. Most of the time, it should involve a Meta discussion, and probably ruling something off-topic, as happened with designer-reasons when this sort of thing was found to be a problem. Quite frankly, the over-use, if not outright abuse, of that policy for closing questions has led me to strongly question whether it’s a good policy in the first place—I would prefer a few noisy, speculative questions over the bludgeon that policy is sometimes used as.
But here, that doesn’t apply. This isn’t a designer-reasons question. It turns out to be an impossible question to answer, but this is not a trivial conclusion. There is no reason to expect that anyone who has this question might already know that. So on its face—not knowing the answers to it—this seems like a valid question. That automatically makes any thought of closing it something that, in my opinion, demands extraordinary evidence of harm.
And we haven’t got that here. We have an excellent answer, and appropriate voting. Those are strong signs that everything is working as expected. Someone asked a question which cannot be answered, and the top answer is a question that thoroughly lays out exactly why it cannot be answered—that is the system working as intended.
From the comments and other answers on this Meta, my impression of those seeking the question’s closure is that they seek more details, tighter definitions of value. And to that I ask, for what purpose? There is no definition of those terms that is going to suddenly change the answer—the existing answer lays out in painstaking detail why it does not matter how you define those things, because you’ll still never be able to answer the question. That suggests, to me, that those voting to close the question are seeking considerable additional effort and detail that will have absolutely no meaningful effect on any answer to the question—which is to say, completely wasted time and effort.
On that point, let me be clear:
We are not here to fetishize detail in questions
The point of details in a question is to allow it to be answered well. Details that do not lead to better answers are not only unnecessary, but often undesirable. Details that just make the question more complicated, but lead to no improvement in one’s ability to answer it, are degrading to the question and the site as a whole.
Details are required to answer questions—but the only details required are those that you actually need to answer the question. If you are voting to close a question due to lack of details, you should be able to articulate why that question cannot be answered without them. And “you might get better answers” isn’t a valid reason (as long as you can still get “good enough” answers, you’re allowed to be satisfied with that—we aren’t here to demand that every querent dedicate themselves to achieving answer nirvana). “It would be easier to answer” definitely isn’t a valid reason (unless you’re arguing you literally cannot fit the necessary discussion and evidence into the space of an SE answer, which I believe is limited to 30k characters—and yes, I’ve hit that more than once). The dividing line here is “can be answered” and “cannot be answered.” Any other concerns are moot after these.
Sometimes the answer to a question is “that can’t be answered.” Sometimes it is “it depends.” And those are both valid questions. Sometimes, to answer, you have to thoroughly lay out the entire situation and explain why there is no answer, or go through all of the factors upon which the answer depends. That’s fine—no, it’s better than fine, it’s an excellent usage of the site, because it takes real expertise to be able to do something like that, and if this site has any purpose at all, it is to be a place where you can find that kind of expertise, which is otherwise extremely difficult to find on the Internet. This kind of thing is literally why we are here.
The judgment call on what should be clarified through comments and edited into the question, and what should be addressed in a thorough answer, can be a difficult call. But I don’t think this question is. And I encourage this community to really consider what expertise means, and what this site is about, because if we aren’t open to questions that demand it, there isn’t much point in this site at all.