The transmission in question isn't your run-of-the mill automatic. It is a Tremec Dual-clutch, made in Mexico. It is made to either go or not go. There is no torque convertor to "slip" when going slower than what would be possible in any given gear, without stalling the engine. When the car encounters those situations, the only way it can cope is by riding the clutch.
In a go-fast car, when the transmission is shifting, the car is not accelerating as fast as possible. When the auto can't switch gears quick enough, then the dual clutch transmission arises as a stop gap measure. Switching gears in a dual clutch is as simple as releasing one clutch and applying the other. It's good, but not as good as not having to shift, so this is the compromise that arises, in order to overcome inadequacies of a power train that needs clutches and multiple gears. I suspect that the need for frequent fluid service is because of the waste products and heat created when riding the clutch is called for by the transmission computer.