Remember... 90 % of pilots killed were killed by the bogie they were unaware of.
Wolf, this may be true but consider that those pilots were playing for keeps. We are playing for fun... the thrill, challenge.
Consider this: Sneaking up on a guy and killing him unaware is fun, but fighting a guy with the end in doubt, can be downright exhilarating. One really good fight is more memorable than 10 vulches. IMHO
I bet you have a better memory of a time(s) where you fought 3 guys, got 2 of them, then managed to slip away... maybe even got all 3.. than you do of sneaking up on some random guy and blasting his AFK butt outta the sky.