I distinctly remember sleeping outside in our front yard as a kid. I can't recall exactly how many times we did this, but it seems more than a few. I remember getting my father's old army tent and setting it up. The tent was basically a canvas covering with two poles and six tent pegs to keep the thing in place. There was no tent floor, just the ground. It basically kept the rain from falling on your face, but it was easy to put up and very, very cool. I wish I had one of those tents now (though, I don't know where we'd store it...).
Tents have changed and so have kids. I think my kids wouldn't mind setting up a tent in the backyard, but pulling out the sleeping bags and air mattresses and finding a place on the floor of our front room is so much easier.
Sometimes on a holiday eve the children will ask--and permission will be granted--if they can sleep in the front room. I wonder if my kids, in 30+ years, will think back on their childhood when their kids do the things that their kids will do. Time will tell...