I've worked in drop shipping for ups/fedex in a large warehouse, and you would be surprised how easy it is to put something on the wrong pallet or truck. Even when I used to work at Canada post (and their system was very organized at the time) it's super easy to send something down the wrong belt. None of that even takes into account the action of taking the customers order and making a shipping label and then spelling something wrong.
Now, now of that is the purchasers problem, but it can be hectic in there.
I respect that and I shall be less harsh, not an easy job for sure. The message should represent the issue that was encountered though, not a generic one stating 'Incorrect Address', that makes the recipient very unhappy camper, especially when they typed out the address as part of the online order.