This guy was a jerk, but I think one problem is that often people who call do not ask the question to the point -- their wording and questioning is ambiguous or half-formed and the people answering the call are not trained in how to elicit the actual question the inquirer is REALLY asking. That's a skill set and unfortunately, one that is often not taught.
As an example, we hired a new receptionist. She sits near my desk and I can overhear her. She's nice, professional, well-spoken and perfectly competent, except she doesn't know how to ask the questions of the ambiguous caller to give them the information they need. Many of our callers here have only a vague idea of what they need and aren't even sure if they're calling the right place. You have to help them ascertain what they need and who they need to speak with. Many have a tendency to tell a long drawn-out story and (honestly) it's often hard to pinpoint the actual point of the story. I've been working with her to learn these skills. It involves listening for key words, knowing the likelihood of various questions/needs being expressed, and how to ask questions.