Generally I pull the flag from 85yds and in after I lined it up. It does nothing to help those shots as most have backspin so the flag is not going to stop anything but the ball from going in. The other reason is what Marioh mentioned, the flag is made of conrete, trying hitting the pin on an easy approaching reflecting spinning off the green, there goes your tap in birdie.
On the other hand, say for example some of the chips in the virtual majors I will leave the pin in if severaly down hill. Need something to apply the brakes.