That would require the clerk to be allowed to do their job. They don't even have an AM clerk where Upstate works.
Or where I am employed; plus, when people "think" they are correcting things in DKE Small, they are only correcting it for a single package when they smash F10. To produce a meaningful effect, you have to use E2DC, AMS, or contact sales who can allegedly talk to the shipper to reflect the "real" address.
As to the Post Office comment, all those updates are distributed electronically, too - very hands off. If the PO screws up, it will filter down to UPS in a weeks time (give or take a day or two) once the PDS' update their standards. And, if the address range doesn't exist according to those standards, it can be pretty difficult to correct properly - as opposed to just giving it to the driver and saying "you know where it goes."