Amazon sends sends the questions out and presents them as if you specifically were being asked by somebody.

It's like if Amazon built a guide map by walking up to people on the street and asking, "how do you get to the airport from here?" and writing down the response verbatim. A reasonable person would tend to respond, "I don't know" rather than ignoring a direct question asked of them.

I think those are a side effect of Amazon sending out emails like 'what did you think of x product? Reply with your review!' after a purchase. Why they don't filter them out, I don't know.

Edit, I mean the ones that ask you questions about a product you purchased

My theory: I think Amazon is showing the unanswered questions to random people, and they answer "I don't know" to make them go away.