If someone asks a question, answering that question feels like the right thing to do.
But it isn't.
By definitely answering that question, you only resolve the problem one member have. That's all you achieve. That member goes away. She has her answer.
Overzealous moderators tend to do this a lot.
They see a question and answer it. Job done. Case closed.
This is similar to the problem with providing all the answers.
The problem with answering the question is it often ends the discussion. No-one else needs to participate in a discussion that has been answered. It doesn't breed the habit of members answering the questions of other members. They wait for the moderator to answer questions instead.
Worse yet, this doesn't get the poster more involved in the community. This doesn't draw someone further into the community. This drives them away.
Far better to ask a clarifying question, to try to learn more about the member, to ask for different members to give their ideas/input, to highlight the question in other material or undertake all the tactics listed here.