I already noticed a certain number of times that some questions have been closed based on the policy for "opinion-based" questions. Reading the rationale for that policy, I find:
Many good questions generate some degree of opinion based on expert experience, but answers to this question will tend to be almost entirely based on opinions rather than on facts, references, or specific expertise.
Of course, I fully agree. However, I think that in some cases, this policy has been used in a too wide meaning. The last example is the question How can I accurately state the uncertainty principle?.
The explicit question was
I'd like to know if there is a simple conceptual explanation that uses key concepts such as "observation," "measurement," "decoherence" accurately. For example, if I were a teacher, how could I state Heisenberg's uncertainty principle in a less mathematical, but conceptually rigorous way?
Frankly, I find it difficult to believe that it is impossible to provide answers to this question not based on facts, references, or specific expertise, and I would say that all or most all the answers, including the mine, were not opinion-based.
Even if it is always possible to reopen a closed question, and I see that the process in progress for this question, I pose the more general problem of what I see as a too subjective use of the policy on "opinion-based" questions. There was already a question here in meta for a different question. Even in that case, I do not see a convincing argument for closing as "opinion-based", although I agree that the question had other weaknesses. But again, the problem I am raising is not the closure of such or such question but the application of this specific rule.