After reading this question: Ought one to answer one's own question? what happens in the case that you know several questions that will further help the community but you want to make the question instead of waiting for someone to make and answer it. For me i find it a little unethical but there has been several questions that i get asked from my students that come up a lot but i have not found the question here and i know the answer.
What happens in this case where you can make the question and the answer in a sense that helps the community and the site. one case is 2 students that came to askubuntu and did not find the question they were looking for. Of course they did not create the question instead they left. But from a point of view, creating and answering a common question that has not yet been asked could help in the search for users of ubuntu in finding a reference to askubuntu about that specific question or problem via google and other search engines or even the askubuntu search box.
This are just some thoughts about my doubt about this subject. With all the respect to everyone in the askubuntu board.