Max reverse thrust is used mainly to save on replacing brakes unnecessarily. Brake usage is high on aircraft on the domestic routes. Depending on the airline, some operators have a "power by the hour" agreement in place for the use of their powerplants. Not sure whether maintenance is factored into this, or if the operator pays for this.
Full thust take offs are avoided as a result to save some bucks, unless needed due to operational reasons. What it means is that the operator is not too concerned about increasing the engine's lifespan, but is more concerned about brake lifespans. It's always an economic juggle. SAA's A340's use a derated climb, also to save bucks. Apparently there is much to be saved in this phase of flight as well.