I lean towards thinking that the question should remain closed, though I could see it going either way.
The question has some positives and some negatives. On the positive side, it inspired answers with excellent information. On the negative side, it is fairly broad, argumentative, and calls for opinions.
In an ideal world, I would suggest that it remain closed (as too broad), and replaced by multiple separate questions, where each question asks about the accuracy of one factual claim.
Currently, the question comes off to me as "here's a long rant I read, is it really true?". The text we're asked to respond to contains both factual claims and judgements/conclusions/opinions, without separating the two out. Because of the mix of the two, I don't know how to answer the question ("is this really the case?") objectively. One can respond to the factual claims objectively, but responding to the opinions and conclusions seems like it calls for opinions.
Ideally, I think it would be more constructive to separate out the specific factual claims made in that argument, and then ask specifically about each of those in a separate question, and leave judgements and advice and opinions out of it, and then ask people who answered with concrete evidence to answer those individual questions. That's in an ideal world where doing all of that work is feasible and successfully leads to all the information being preserved in separate questions. I don't know whether that will actually happen.
I should also share a personal bias: I tend to be wary of posts with a strongly-expressed argumentative position, that ask us to respond to that position; I'm not sure they make a great prompt for a great question. So, it's possible I might be reacting to that aspect of the question as much as anything. It probably shouldn't affect the decision of whether to close or not, but it probably does affect me.
That's just my view. I don't see this as clear-cut. I can understand how people would come to different views. For instance, given the outstanding information contained in the answers, I could appreciate a view that the positives outweigh the negatives. I could also appreciate a view that says that Academia.SE regularly deals with calls for opinions and advice, and as long as they are supported by evidence, that is acceptable.