You and the OP are talking about 2 different things. While he mentions "global KDR", he is talking about the KDR for all kills and all deaths globally, not the median KDR for all players, which as you point out is probably actually slightly above 1. While I agree that your way of looking at it is probably more accurate (especially if asking the question "is my KD better than the average player's?") you can't argue with people that do their math the same way the OP did. It's two different but reasonable ways of looking at the stats.