Everyone seems to miss the simple concept for every kill there has to be a death, and how it effects the distribution.
I don't think everyone misses the point. I've argued for it in on multiple occasions, and others have too.
However, the general intuition is that if 100 players all had individual K/D scores of 1 after a year of arena combat, it would indicate much more equal skill levels than if among 100 players 5 had K/D scores above 2, 20 had K/D scores above 1, and the rest had K/D scores <1.
Edit: I've got to think about this some more.