Yeah Bob, we know all of that. In a perfect world, we would all just size our pumps exactly correct for the application. However, if you need 1 HP worth of water some of the time, and you only need ½ HP water at other times. Saving 16% in energy while you are throttling the pump is a good thing.
Your other options are to allow the pump to cycle on and off at 100% power, plus the 6 to 9 times the power required for every start of the motor. Or you can use a Variable Speed Drive, which will also reduce the power consumed by about 16%, just like throttling with a Valve.
Both of these other options are extremely hard on the motor. Running at 100% power and cycling on and off into a pressure tank is one of the biggest killers of motors. The Variable speed causes harmonics, voltage spikes, resonance frequency vibration, skin effect corrosion, and other problems that will also kill a motor.
Throttling with a valve eliminates cycling and all the problems caused by VFD controls. In the real world, a pump can never be sized exactly to the demand, because demands always vary. The way people use water in this day and age requires the pump to deliver different flow rates at different times. Throttling with a valve is the best way to accomplish this task and make the pump system last longer. 73% more energy per gallon sounds like a lot but, depending on how much water is actually being used, may only be $5 per month. $5 per month is a small price to pay to triple the life of an expensive pump system, while being able to use water anyway you want.