If this Qantas policy is true surely it is false economy. How much extra fuel was used as a result of the diversions?
In theory, if only minimum operational fuel was taken on every flight (i.e. no discretionary), even with 2 diversions a week, the savings would be 8 figures a year. However, the costs are based on quantifiable factors, which do not include loss of business due inconvenience and the negative media impact.