When we help people in support we want to quickly solve whatever problems they face. There is an urge to get the answer sent as soon as we can. The faster reply is the better reply. But, that is not always the best way to make someone happy. For those people who are frustrated, shy, or unclear in their original description, you may end up solving the problem as you constructed it, not the problem they had.
This problem is exacerbated when you face a backlog of requests. Someone has already been waiting for days so you really, really want to get that answer to them. Now.
Sometimes, the best thing you can do is ask a question. Patience and care trump raw speed.
Taking a step back gives you both the opportunity to make sure you are on the same page. You show that you are there to help. You want to do more than send a response and move on. You want to take time, understand things, and then solve them. When you do this you work toward honest help, not just efficiency.
The less we assume the better we will be at making people happy. Good support is about answering the questions someone has. Ensuring that we properly understand those questions is the most important step toward that goal.