If one reads the description of this site, one finds that it's purpose is:
Programmers Stack Exchange is a question and answer site for professionals and students in software development and related fields who are interested in getting expert answers on conceptual questions about software development. (emphasis mine).
To my mind, conceptual questions are ones that will almost always require opinion-based answers. Yet, reading further down the site description, there are the statements:
Focus on questions about an actual problem you have faced. Include details about what you have tried and exactly what you are trying to do.
Not all questions work well in our format. Avoid questions that are primarily opinion-based, or that are likely to generate discussion rather than answers.
These two statements appear to be directly copied from Stack Overflow, which isn't a place for conceptual questions; it's focused on specific questions about specific issues. These two statements also seem to run counter to the stated purpose of the Programmers site itself.
Recently, I answered Why is it inappropriate to use UML diagrams to plan how your code will be organized?, which seemed an almost perfect fit question for this site. Yet this question was closed as "primarily opinion-based". Whilst it has subsequently been re-opened, it's worth looking here at the words behind this close reason (taken from Stack Overflow, but I assume they are the same for this site):
primarily opinion-based 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 facts, references, or specific expertise.
It clearly states that "Many good questions generate some degree of opinion based on expert experience", which I believe was the case with this question. This raises the obvious question: why did those that voted to close it feel it was too opinion-based?
Clearly a question such as "Should I use spaces or tabs for whitespace in my code" will be purely opinion-based and such edge-case questions deserve to be closed. However, as mentioned earlier, I feel answers to conceptual questions will almost always be opinion-based. Thus my question, should this site even be using this close reason, except for these rare occasions?