The KFC near us is just terrible. This isn't surprising at all.
There are good and poor KFCs (and other fast-food outlets) near us, some poor, some decent (and some that have been both at different times). The concept of a franchise is that it's a replicable complete package that, if located properly and done to the letter, it will satisfy customers and be profitable. "Done to the letter" means that any location is going to be as good as the people working there. My guess is that that KFC has manglers and people cutting corners, and maybe manglers who drive away good employees. If that KFC has high employee turnover, manglement is the probable cause.