A module specific question, such as How can I tell Drush in which folder should a module be copied? is absolutely appropriate to be posted at drupal.org in the module issue queue. I don't think such questions should be posted here.
Questions about modules are welcome here, but drupal.SE is not a replacement for a project issue queue.
If the question is about how to do something with a module, how to use a module API from a different module, how to alter the output of a module with a custom module, the question is fine.
If the question is about a workaround for a bug in a module, then the question is not probably fine for drupal.SE; it would be fine if the bug has not been yet fixed after months, but it would not be fine if the maintainer already fixed the problem and he just need to create a new official release of the module (in such cases, the question could be considered too localized).
What we should avoid are questions about bugs that don't get any answer, or for which the reply is simply "this is a module bug." Both the type of questions are not "healthy" for a Q&A site, especially one that is still in beta and it will be evaluated in 63 days.
First, for (dare I say) a lot of modules, the issue queue can be a bit of a graveyard and only those who have specifically subscribed to that specific module or happen across it in a larger feed would ever see the issue.
Drupal Answers (like drupal's mailing lists) let people pose questions to the community at large - so response times are much better.
I think the other questions posed at: Avoiding easy questions and https://drupal.meta.stackexchange.com/questions/7/what-questions-are-on-topic-and-what-questions-are-off-topic could provide some insight in whether or not this sort of question is viable for Drupal Answers cannon fodder.
BTW isn't to say I don't sympathize with you, and if someone doesn't RTFM I think we should stand against it (as IRC channels do to an extreme) - but more likely we would quickly and directly ask them to read the documentation in the area marked "Your Answer is Here" etc.
I think module specific questions are OK. There are a lot of views specific questions here already.
Where the line is, is for raising bugs for modules, that is where the issue queue is applicable.
The majority of modules is used by < 200 people, so, unless a specific module-maintainer or author uses stackexchange on regular basis, especially in the long tail of modules, Drupal.stackexchange.com will grow a large set of unanswered questions. That, again might fire back on stackexchange Drupal.
If we can raise some bar, we can avoid that: only questions on "popular" modules are allowed. And "too specific" questions can be closed, marked "too domain specific".
Problem: when is something popular, when is it "too specific"?