i have used dme many times and must say that i love it.

it saves me a lot of money and problems.
on most occasions my pickup time was about 3 hours ahead. i don't mind being at the gate an hour ahead to avoid the blood pressure boil caused by having to worry.
on my last trip i had a pick up time that was a little closer and did question that. i arrived at the pickup area 20 minutes ahead and soon a bus pulled up. the family checking their luggage ahead of me were to be on my flight and when that bus pulled up, i thought i would be on that one. the other family got on and they told me to wait for the next bus. then a family had overslept and the father came out to have them hold the bus until every one was there. they held the bus for 40 minutes. i was getting worried. i arrived at the gate as they were closing the plane door.

that was not good.
this might be ok for most and would have been for me when i was younger. i have a major hip problem now and can not move very fast. i can use scooters on disney prop but they don't go to the airport.
i do think it would be polite of someone who is very late for the bus

to take a cab and let the bus move on. after all, dme is free and should not be abused.
maybe they need to make a few new rules.,,,,,,but this is the first time anything has ever gone wrong for me.