And some games can be plenty challenging while taking away the kill portion almost entirely. Take Swat 4 (co-op) for example, better scores and more challenging when not going around popping everyone with 5.45nato in the head. Most hard opponents manage to go down with at most a round or two of 9mm jhp to the leg. Only noob servers allow player to go around killing everything.
I do my gaming for the thrill and felling of achivment and I play any game as long as its good unless its sports those bore me.