There are two criteria being evaluated in this discussion: quality of the question, and quality of the answers.
For the sake of discussion, let's say quality can either be high or low. For this discussion, the querent is putting forth: what if there are high quality questions that receive low quality answers?
The thinking is that if a question is low quality, it will always attract low quality answers. Whereas, if a question attracts low quality answers, the question must be low quality as well. Well... not necessarily. This doesn't always happen in practice.
For an example of a well-formed question (as decided by the community), take the following: What level should this exhaustion-causing spell be?. While it is open now, it was closed twice and re-opened twice.
There was a meta discussion regarding this in which it has been expressed that this question is still too broad and opinion-based, even after the 2nd re-opening. Because of the apparent lack of great answers and visibility, a Bounty was also placed on this question by Ceribia.
The top answer for the linked meta discussion states the following:
This is an example of a question being declared subjective because it's pulling subjective answers. In some other world where it didn't, it would be fine. But the assumption is that if a question is pulling subjective answers there's something wrong with the question. So it gets closed to retool.
It seems, then, that the closing of the question was because it pulled in bad answers. But the quality of the question itself is not actually poor. A support of this is (1) the decision of the community to keep the question open, and (2) the similarity of that question to this and this -- similar questions which were not closed for pulling in high quality answers.
In other words: it can be shown that in reality, sometimes, a good question does get closed by no fault of the querent's, but simply because it has attracted low quality answers.
As such, we should be able to close questions with the reason that the answers it has pulled are of low quality, and not because of the question being of poor quality itself.
Another answer in the linked meta discussion brings up the alternative option of aggressive answer deletion instead of closure of otherwise good questions. This can be considered as well, and while it seems like it might be controversial, it does seem like a good solution for, say, answers with very low scores due to a large amount of down votes.