People occasionally ask questions of the form, "Why does language/API/etc allow/forbid/not implement feature X?" What is the policy, if any, for such questions?
Sometimes these are rants in disguise, a way of writing, "Lanugage/API/etc annoys me because it allows/forbids/doesn't implement feature X" in the form of a question. Obviously, these should be closed as non-constructive and likely deleted.
Other questions are genuine inquiries, people looking for actual information. Some of these questions work well within SO; they do so because the reasoning for it is something that is known or well-understood. In these cases, the answer is either fairly obvious to someone in the field or the subject of publicly available information that experts in the field know.
For example, if someone asks why Lua doesn't allow constructs like "value++", it can be explained. The reasoning behind the way Lua forbids expressions from changing the value of local variables is well understood and has been explained via documentation from the language's creator. Many Lua experts would be able to answer such a question, even though they were not directly involved in the language's creation.
My concern comes from questions which are clearly not rants, but the actual answers for which are not widely known. By that, I mean that the only people who actually know the reasoning why feature X is allowed/forbidden/not implemented are the people who were responsible for developing the specification/implementation itself. Only the owners of the language/API/etc actually know the reason why they made certain decisions.
What this often leads to is a form of popularity contest. People offer varying opinions about why the feature is the way it is. Some of them are well-reasoned and some are not. The concern is that the answers will ultimately be speculative; as such, people will either vote for the argument they feel is stronger or the opinion they agree with.
That's a lot like a poll question, is it not?
Now, it would be easy to just say that such questions should be closed. Except... sometimes the actual authority(ies) in question are here on this site. Howard Hinnant is a member of the C++ standards committee and has, on a couple of occasions, provided insight into the reasoning behind certain C++ standards committee decisions. If we simply shut down such questions, we wouldn't be able to get his insight on them.
At the same time, if an authoritative source is not forthcoming, then it becomes a free-for-all of everyone posting their own belief about why the language/API/etc is the way it is.
Is this a problem or concern? Do we need to decide on some form of policy? How do we balance the needs of keeping the site clean with allowing authorities to participate and bring their unique insight into Stack Overflow?
As an example, consider this question*. Many people can post reasoning, and quite justified reasoning. But unless you were actually on the standards committee, then there's no way to know whether any particular reasoning is the actual reasoning they used.
* I didn't post this solely because of this question; I've been thinking about this for a few weeks now. This question was more of the straw that broke the camel's back.