Here is what Tony Stoltzfus says in his book Coaching Questions: A Coach's Guide to Powerful Asking Skills on why ask questions:
Why ask questions, anyway?
What's the benefit of using coaching questions instead of advising or telling in a mentor or consultant role? Quite simply, questions hold the power to cause us to think, create answers we believe in, and motivate us to act on our ideas. Asking moves us beyond passive acceptance of what others say, or staying stuck in present circumstances, to aggressively applying our creative ability to the problem.
Questions also redefine relationships between people. When I am advising, mentoring or consulting, I'm the expert. My role makes me your superior (at least in knowledge). But when I'm asking you for your ideas, I'm a peer. Questions honor you as a person and communicate your value as an equal.
And because this asking approach changes the relationship, it also changes you. Have you ever left a conversation thinking, "Boy, that conversation was one-sided! The whole thing was about him." My wife calls that a lack of "conversational generosity". We all hate it when others can't stop talking about their own thoughts and ideas—but we're blind to how often we do it ourselves.
The coaching approach forces your conversations to become less about your thoughts, your input, and how you can steer the dialogue around to the answer you think will work. You start listening—really listening—to the other person. You decrease what you say, so that others can increase. And that's where the magic happens: the more you listen, the more you see how capable they are, how much they can do with a little encouragement, and what wonderful individuals they are. The more you ask, the more you love.