I've honestly wondered the same thing and seem to have got my answer from this thread, so thanks for posting it. I'm in the opinion the only thing that should be getting Saturday 12:00 commit is medical packages, time sensitive paperwork (though I don't know what that would be on a Saturday since most places that would handle things like that, such as banks and investment places, lawyer offices) are closed typically.
I feel as though we go about Saturdays entirely wrong now. In the past we would have part timers (air drivers or lower seniority guys inside the building) who would drive air and get at least some area knowledge. Now it's just full timers here that drive Saturday, whether 22.4 or RPCD. I feel we're losing out some of the potential training that Saturdays have to offer and are just treating it as another day - which we are doing now.
What if we still had the inside guys run air from 10:00 to 12:00 or whatever your local times are? Some here reach out to 1:30. While having said that, we could potentially run ground routes earlier from those wanting the OT/22.4s/lower seniority guys so they can have the bulk of the routes completed as well as pickups back earlier.
Sorry for the rant but it's 2 AM and time to go to bed apparently.