I didn't read this as expecting simple answers to questions, but as the question being simple and instead of the person being asked giving a direct answer to that question, instead they give an answer to a tangential question.

I've worked with people who do this consistently. Know this I would try to formulate as simple and direct a question as I could, but always the answer would be to a tangential, often more basic question.

At first I thought maybe the person was being condescending, answering basic questions that weren't asked, that anyone in my position should know. Maybe he was, I still don't know, but I refused to "believe" that. It's tricky suspecting something but forcing yourself not to believe that thing, but it was very helpful in that I was prepared to get past the initial phase of him not answering the actual question without it being contentious at all.

I agree with OP, it does seem like a lot of people make no effort to communicate clearly.