That's funny, because they kind of did for awhile.
My brother (a West Point grad) had an old jeap that the army decided should be replaced by a Chevy Bronco while he was stationed in Germany. Lordie, how he hated that Bronco. The thing got stuck if it thought about raining and it broke down all the time. He'd b!@#$ about how he could fix the jeap with a screwdriver and a pair of pliers but it took a "Certified Mechanic" to do anything on the Bronco.
He was also forced to carry a Barreta 9mm as his side arm for awhile too. After the breach broke on his 3rd one he petitioned for and received a waiver so he could go back to his Colt. So did his commanding officer.