I read about people struck by lightening on Half Dome. I still went. So do thousands of other people who don't get struck by lightening.

You have your reasons, I have mine. I like to stand up instead of changing clothes lying down. I like to cook under my tarp. I like to avoid hoisting myself up off the ground where I spent my whole night tossing and turning without sleeping. You are welcome to sleep anywhere you like, allow me the courtesy of doing the same without being heckled for my (perfectly valid) choices.

Think about the materials the native americans had on hand and whether they would make a comfortable hammock. I am certainly not going to take a hammock made of plant matter out in the rain. And that's a red herring argument anyway - if you are going to limit yourself to what historical people used in various locations, throw away your backpack, your nylon tents, your handy little cookstoves, your synthetic clothing, your fancy boots, and those store bought freeze dried meals in those little foil packets. Just because your great great great grandpappy didn't use it does not mean a particular item of gear is not useful today.