In many cases these lists were started by insurance companies of the campgrounds.
Let's face it: Insurance companies are experts in statistics, and the breeds that bite the most or cause the most damage.
So if an insurance company says XXX breed is a high risk, and the figures are accurate, I would tend to believe them, although I would not like it. There are so many variables and the individual dog is not considered.
After all, the analysis and reduction of risk are two major components of the success of an insurance company.
Simply, it is what they do.
Not saying I like it, or agree with it, but then again there are other things in life I am not happy with either. Just the way it is.