Just A UPS Guy
Bully.
Why would they? It's going to be full time driving at a lower rate than regulars.
Short-sightedness, that's why. It helps them now so they don't think about 2, 3, 5 years or more down the road.
Similar to why you think it would be ok for you to deliver ground at your rate to deliver on weekends. It works for you, so it's fine. Well, it's not fine, it's a full day of ground work, it deserves ground pay.