Shellrider:
The challenges at Scatsta are the weather, adjacent terrain and limited apron space.
Not forgetting the short runway, with downward slope from one end, and the fact the airport only has a single NDB approach aid, with NDB approach on one runway only (followed by circling approach to the other runway - the one with the downslope - if required).
If safety was uppermost on Shell's list of priorities, why was the operation moved from Sumburgh, where there are longer runways, better approach aids and less hazardous terrain? I believe the reason was to save money?
The rigs that SCS serves are also a similar distance from Bergen, which has a much longer runway, better approach aids and facilities, and is much better at coping with winter weather than SCS. Again, perhaps viewed as too expensive for IAC?
Therefore, imposing these experience requirements might be viewed by some as the low-cost option, and is not necessarily the safest one.