It is the duty of the military to kill the enemy. It is also the duty of the military to treat the killing in a professional way.
We have a professional military not simply because they are paid. Being paid to do something does not make one a professional.
What makes one a professional is the adherence to a set of ethics that governs actions.
. That's what makes someone a professional.
Killing and death are part of war. But a professional soldier derives no joy or enjoyment from killing. It is a duty and he or she takes pride in fulfilling their duty, but to derive pleasure out of killing is not the sign of a professional military member.
Just an old vet's opinion.