As they should. FedEx's customer in this instance is Amazon, not the receiver of the package (who is a customer of Amazon, and Amazon alone). If anyone has the clout these days to hurt FedEx economically if they don't improve, it's Amazon. Amazon should be pushing FedEx (and their other shippers) to be more accountable for late, damaged, and lost packages.
These days both FedEx's and UPS's preferred delivery method seems to be to rake their hands over every single door buzzer to my apartment building, dump the packages outside (insanely unsafe), and run off before anyone has a chance to respond to open the door. They even do this for signature-required packages on occasion, forging the signature. I get that drivers' incentives are completely screwed up regarding how their performance is evaluated, but it's a terrible experience from my perspective.