Beyond all that has been said so far, maybe I can come up with a different perspective. Given that you're tankering fuel on a sector of non-critical length, you don't have the extra time during the turn-around while waiting for the refueller to arrive and do the job. This probably translates into a fairly significant time saving in the schedule, allowing the aircraft to do one extra flight each day or maybe just each week.
The company ends up with better utilisation which can translate to additional services, or in reducing the duty hours of the crew (that's probably a bit too altruistic though!
). Perhaps it might also mean that the company can make their crews work longer each day without having to pay them extra.
In any event, a shorter turn-around time might be better for achieving ATC slot times. Well, even if that's not true, a shorter turn around time probably results in greater operational efficiency for the company.