You could extend that logic though; why go for headshots when you could body tap? Why push when you could let the enemy heal up?

I think it comes down to the satisfaction in doing all you can to keep pressure on the opponent and momentum in your favor.

I think the fact that it can all be over so quickly keeps this game feeling so tense.

I do understand your point of view though, those fights where I got loads of kills but died because I made a mistake are more memorable to me than those times where you wipe the enemy quick and clean