i think a big part of it is to keep guys from taking bad shots. ive heard stories of guys trying to take 2-3 birds with 1 shot. or guys just open up after he drops the first one spraying lead all over...

or maybe to limit guys from taking too many birds from the same flock.

i remember i was young..dad and i met a guy from virgina or west virgina or somewhere..we were having lunch after hunting and were talking turkey hunting. he told us hes gotten 2 with 1 shot plenty of times...this year his goal was to drop 3 with one shot. he said somethin like "its hard to get them buggers lined up right!"