He was not writing about camping in campgrounds; but rather wherever you decide is a good spot to bed down for the night (he gives advice on finding good places). You can tell by reading his work that he was into the doing rather than appearance of doing - he doesn't recommend you head down to REI and buy a couple thousand dollars worth of gear - he starts with the very simplest camping that he did with a wool blanket, tarp and a wood fire in the 1970's and then explains what additional equipment he used as he rode on many bicycle camping trips. This page provides a discussion of equipment, and lists what he carried with him.
This is a quote from his page -
"I have never forgotten the answer someone received on a Sierra Club hike. He had simply asked what minimum equipment he would need to start camping, and the person leading the trip -- who evidently considered himself a great expert -- rattled off the brand names of and details about hundreds -- if not thousands -- of dollars of equipment, saying each item was absolutely necessary. Actually, on a warm night in many areas, one can sleep right on the ground without any gear whatsoever, although a ground cloth would be a good idea. I have slept without pitching my tent many times (I've also had to pitch the tent in the middle of the night too, when the weather changed). But my real point is that it doesn't take first-rate equipment to have a first-rate time, nor will first-rate equipment do you much good if you don't understand what you're doing."
Ken Kifer spent many years doing what he wrote about. He was killed, by a drunk driver in 2003, while riding his bicycle. His website is kept up by a good friend.
