This. Your edit is what I've always said. .5 KD basically represents a negative number (for simplicity sake). So you have to inverse to get proper KD. True KD, discounting suicides, is exactly 1. But the average KDR (ratio) is not a true representation for the exact reason you said, it weights the positives more. The true average KD across all players is 1. The GG averages and bungie's averages just pull the straight ratios without the proper conversions.