It is a very good idea to add the "general reference" reason to create them as wiki if there is no other similar question already in SO. Basic knowledge is also useful for many. But, in the case there is already one question about it (and, in those cases, there are usually many), the "exact duplicate" flag should take care of it, so I don't see it convenient as a reason for closing a question.
Truth is, many beginners may log in to SO and ask very basic questions and never appear again, but others may learn from the feedback and become productive members. Having those wiki questions will still give them the answer they need, while removing the duplicate questions should take care of the clutter.
Addendum:
SO has already an engine to read your question while typing and suggesting related questions. How hard would it be to also link to the official documentation, at least for the most common problematic languages (c#, java, html, etc)? I'm sure this issue is not a big deal in perl, lisp or assembler questions...