Some questions contain curious hoops or preemptively reject valid answers/solutions and don't explain the reasoning behind the rejection? **Should these be downvoted?**

Examples are:

 - I don't want to use [some functionality of the language or API I'm using].
 - I want to do this in only one loop. (But doesn't count built-in iterating functions as loops.)

...anything in this style, *as long as no explanation is included* in the question. Raymond Chen describes it well enough [in a blog entry][1]. I'm not talking about people who simply state the external requirements of their code and go on from there. I'm talking about people who avoid solutions that would actually solve the problem while meeting their requirements.

The reasoning is this: Preemptively rejecting solutions or presenting hoops *without providing reasoning* implies that there *are* some requirements for the project but, for some reason, they are not included in the question. This, in turn, means that every possible answer that can be provided may also be deemed invalid a posteriori by the asker due to some criteria that aren't known initially (or at all). In other words, it doesn't make clear which kinds of answers are "fair game" and which aren't (though it implies that there *is* a distinction). And that lowers the quality of the question, in my opinion.

Clarification: This question is *not* about agreeing or disagreeing with an asker's opinion.

  [1]: http://blogs.msdn.com/b/oldnewthing/archive/2013/02/06/10391383.aspx