It shouldn't be the developer's burden to ensure that the reviewer is operating above the reading level of a toddler. I am sorry that your boss apparently cannot, but that's not justification for all industries to operate that way. The purpose of a camera app is to take photographs. A user who downloads a camera app probably wants to use it to take photographs. This is something a child can understand. If I have to hold the reviewer's hand and explain what a camera is, I severely question whether that reviewer is qualified to be doing that job.