As campers ourselves, we knew what was important for a comfortable stay when setting up our site, we have five tipis, but have four showers and four toilets separated into male and female blocks, always clean and always hot water on tap, lack of showers/hot water and toilets that are not kept clean is probably the biggest complaint of most campers. We also decided to include breakfast in the price, as this is the meal most campers dislike making, our guests tell us that crawling out of the tipi in the morning and heading to the dinning room for fresh our fresh baked pastries, bread and coffee are what make the holiday luxury camping. The trouble with many campsite owners is that they are just in it for the money, they will cut corners wherever possible, providing as little as they can get away with is their default position, rather than providing the best they can.
As for providing individual facilities, this might work if you have two or three units, but on larger sites the installation costs and maintenance costs would be prohibitive, not to mention the environmental costs, all our facilities are in buildings that were already there, i.e barns, to erect lots of new buildings for facilities, would surely go against the reason for camping in the countryside.