Those reviews always amaze me.

And the people who answer one of the questions with "I don't know", too. Why did they bother typing anything at all?

My theory is that some people can't imagine that people aren't talking specifically to them. You see them in chat rooms answering every question as if it was posed them to directly, even when it was obviously directed at someone else.

In the case of amazon questions, this is a lot to do with how amazon handles them. If a new question is asked, amazon will sometimes send emails to people who have bought the product with the question. It's quite easy to see how someone could think this is directly addressed at them.