Ive never had a KD above 1.5 in a BF game. And Im a pretty decent player.
There are a few reasons for it, as Im far to aggressive, and dont tank/chopper whore nearly enough to maintain a super high KD. Its really hard to have a KD higher than 1.5 when you almost always play infantry too. I also have a tendency to wander off on my own as I like to be constantly moving. haha