I make a habit of commenting if I downvote, sure, the commenter might not like what I have to say but I feel I owe it to them to be as honest about why I felt they weren't contributing to the discussion.
To answer your question: "how can you disagree with a question"; well, you can downvote a question that is loaded (with some kind of ignorant agenda) or a question that is so blisteringly ignorant by itself that it is plain and obvious that the commenter didn't read the article posted, even a skim-read.
To answer your question: "how can you disagree with a question"; well, you can downvote a question that is loaded (with some kind of ignorant agenda) or a question that is so blisteringly ignorant by itself that it is plain and obvious that the commenter didn't read the article posted, even a skim-read.