Why do people go car camping?

We use our vehicle to get to places where there is no other vehicle or building in sight in order to camp.  To be sure, some people like to camp in developed campgrounds but that is not my experience.  While we used to backpack often, it is just not feasible to do so with small children.  Our honeymoon was two weeks of camping along the Arizona Strip (the area between the Grand Canyon and Utah) and we took a vehicle so that we could explore more areas than we would have been able to on foot or horseback.  We didn't sleep in our vehicle then because it is pretty impossible to sleep in a Jeep.  Even though we have a bigger truck now, it would still be uncomfortable to sleep in it with two adults, two children, and dogs.  Also, when car camping you can set up camp and then use your vehicle to get to the trail heads for a multitude of hikes.  For example, we can set up a camp and then travel to a wilderness area, put the smallest child in a back pack and hike for the day, returning to camp for a campfire, dinner, and an air mattress.  There have been a few extremely cold/wet nights where I have taken the kids into the truck but I wouldn't say that I slept (although they did.)

Tents & air mattresses are more comfortable than cars.  If you're car camping you can bring a degree of comfort, but still experience the outdoors, sit around the fire(a lot of places I've backpacked didn't allow fires), and get a degree of silence and beauty in nature.  If you're car camping there is a good chance you aren't going in the rain, and I do know people who've retreated to their cars in those cases. A good rain fly will help though.  Also, you've got room in your car for that spare tarp, rope, bungee cord, popup to block the worst of the sun, ice chest, beer, water toys if you're on a river or lake... kids too small for backpacking, etc.  Many people want to cheaply go somewhere, be near nature, but don't want to be minimalist about it.  Why not bring a stove? and a dutch oven while we're at it?

Simple, because sleeping in a car is not camping !!! Seriously, people use cars to get to the place where they want to camp (otherwise how would they get there, with public transports generally not connecting these places), but that doesnt mean they want to sleep in the car. They want camping.

I grew up in a family of backpackers and for a long time could not understand car camping. Then I married a girl who spent her whole life in Brooklyn.  To her, a barbecue is "camping." So... I say it's all a matter of degree.  Folks who do mountaineering probably wonder how my backpacking "counts" as outdoorsmanship. Over the years, I've come to rather enjoy car camping, now that I understand it a bit better.  Fat steaks and beer sure beat dehydrated mac and cheese!