I was carrying a pocket FAK and found it to be useful - particularly the band-aids/moleskin/antiseptic. I thought the same thing as you did until I looked at the maps and found that the Disney first aid stations were usually located only in one place in each park. It seemed to me that having some band-aids to put on a blister or cut was better than having to track down the first aid station. Why let the blister get worse?

I completely agree with you on the serious medical issues. I understand that Disney's medical staff is well-trained and well-prepared.