Is this Delta policy or an employee trying to streamline things on his/her own? The coach cabin is usually filled from the back anyway, so how much time did this really save? 3-5 minutes? This is really cutting off your nose to spite your face.
>>bags in the aisle<<
My sister once told me that on certain Asian airlines, this is common. If your bags are in the overhead bin above someone else's seat, they will just remove yours, place them in the aisle and put their bags in. "My seat, my bins" was the attitude. Urban legend?