So you spend thousands of dollars to come to the US to visit some national parks with your family only to have to deal with a concentration of drones on the day of your visit? Now think about thousands of people who this would affect for that one day.
So I can go to the National Parks and enjoy them, but under your requirements instead of mine. We should ban terrestrial camera too, some of them make noise when you take a picture.
Blanket bans are ridiculous and lazy. Particularly considering how many people actually own UAV per capita. The parks aren't going to be overrun with drones.