Kuduka has hit the nail on the head there. A few people log in the early hours of the morning to suck up all the ore on the server and sell it to the numerous POB's sitting in the fields which leaves the fields completely drained. This puts an end to any sort of mining later on in the day when the server population is at it's peak (because European evening).
Ofcourse this debate has already been had and since field drain has been turned off I have actually seen more mining going on because suddenly you don't have to spend 3 hours filling one ship up.
On the plus side, although field depletion is turned back on, when the gold fields were full and I was using the Surveyor I managed to get an average drop rate of 18 in the BMM field (rounded to the nearest 0.5 and taken as a mean from shooting 100 rocks).
