Shawn,
I think the basic response is that operators have to provide as many seats as possible....and Cat A vice non-Cat A translates into 1-2 paying seats less per takeoff. It is also probably fair to state that oil companies usually give mere lip service to safety and revert to the Risk management mode when calculating safety costs....as compared to operational costs.
An example, a rather well known oil company and a large helicopter operator agreed to compromise on reject areas after selecting Cat A standards for their Bell 212 operation. One of the compromises included the approval for the operator to use canals and rivers as an authorized rejected takeoff area following an engine failure on takeoff from land based helipads. The decision was predicated upon the cost of preparing long, smooth, firm, and even landing surfaces for the aircraft. The Cat A takeoff profile itself was altered to provide some semblence of a normal Cat A profile to fit the very short dirt reject areas available. No thought was given to reducing the takeoff weight (based upon seating) during this process. The good news is .....to date there has not been an engine failure on takeoff that required an intentional reject into the water on that operation. The modified Cat A takeoff profile placed the aircraft smack in the middle of the shaded area of the WAT Chart....and was merely an old style US Army confined area takeoff over barriers 150 feet high...that is ...up, up, and away on a nice angle to 150 feet with a reject area as short as 250 feet. The profile seemed to work...but the thought of landing in the water as an approved reject area sure seems unwise to me.