@tonydennison is right about the FedEx company. FedEx Ground is and has been a separate division that employs independent contractors as drivers. There is no incentive for them to do quality work; the attitude is get these packages off my truck and go home. It doesn't matter if it's the right address.
Take a look at FedEx Express next time. It costs more but so does UPS. BTW, I have noticed improved service from UPS.