To evaluate the performance of an aircraft(speed, climb, turn rate, energy), we use True Airspeed, not Ground Speed. Ground speed is mainly for navigation.
If you "hover" in a 200 kts head wind, cut your thrust and you will get negative ground speed. If you use ground speed for kinetic energy caculation, you will find it's increasing. That's not correct. You must use True Airspeed, which is decreasing.