A directory is a printed document. It stops being valid the day it is printed on the paper. I am not sure what else you'd expect? Good Sam has no control over whether a park is going to hold up their end of the bargain in the future, AFTER the directory is printed. Come one. You act like Good Sam owns the parks and has control over them. The idea that there is perfection in a directory that has 14,967 independent campgrounds in it seems like a huge stretch to me. If that directory is 99% accurate, that still means 150 errors. I'll gladly pay $9.95 for that as a tool.
While I've read a few posts here about discounts problems at a particular campground, what I haven't read about are locations that got added during the year and the customer received a discount that they didn't expect. And you can bet money that the latter has happened as well.