I fail to see the point of parking somewhere, then moving to take the parking spot of someone who left while you were still in your car. Yay for you, you just got 3 spots closer to the door.
I understand if the parking lot is full, like my building is after about... 8 am. After that point, you pretty much only get a spot at the edges, or if someone leaves. But on weekends, there's usually less than 10-15 cars, and there's tons of close spots.
That's understandable. My parents live behind a college, and though there's large parking lots, it's not enough and kids still part nearly all the way to their house. (They're probably about 3/4 a mile from the school.)