Agree with both hikermor and Montanero. A camera is not a survival essential, but as long as it's bundled into a cellphone, there's no reason to not take it along.

The only possible use I can think of would be to document where you've been by taking a picture of your back-trail so you can more easily recognize where you need to go and keep from straying. I can think of other items that would fill that role better.

Not every item that you take camping needs to have a survival role. Someone is just rationalizing a purchase they don't really need.