why would the "Fleeing Felon Doctrine" be declared unconstitutional?

2 answers

Under U.S. law the fleeing felon rule was limited to non-lethal force in most cases by Tennessee v. Garner, 471 U.S. 1 (1985). The justices held that deadly force "may not be used unless necessary to prevent the escape and the officer has probable cause to believe that the suspect poses a significant threat of death or serious physical injury to the officer or others."

Why is this? Just committing a felony is hardly a death penalty offense.
thank you