Amazon just cares about the lowest bid. They still use LaserShip, for example, who has a long-standing and well-earned reputation for being the worst shipping service ever.

I got something sent next-day via Amazon recently and LaserShip made an extremely half-assed first attempt. I had to spend an hour on the phone with a LaserShip rep and pass my phone number along to the driver (who is an independent contractor) to get a second attempt that same day, after they tried to punt it to the next day with no guarantee that a better delivery attempt would be made (I live in a no-doorman apartment building).

The interesting thing is that I wouldn't have even have been able to complain to Amazon until LaserShip noted that they completed delivery -- so I could have spent days or weeks in limbo.

If there were checkboxes on Amazon where I could choose which carriers they couldn't use, I would...even if I had to pay the difference in shipping.