Questions should point towards solutions. When you question something, you should have a hypothesis – a theory that the questions are meant to test. A point you’re trying to reach.
Questions for the sake of curiosity are fine, of course. But also remember that the time of others is a limited resource, carefully given. When you use your own time, feel free to indulge in boundless intellectual investigation for its own sake – that’s how the world is discovered! (And to my children: your dad always counts – his time is always freely given to the insatiable curiosity your beautiful minds possess.) But when engaging with others, your inquiry should be leading somewhere. To a proposed solution, an engagement of some kind. If you aren’t, then you aren’t making the best use of your – or their – time.