The higher the k/d someone has the lower it is somewhere else. Proving that if there are very high k/ds then someone has the short straw and that also means for people to have high k/ds a vast majority of players must be very bad.
This can be backed up, my kd is 1.80
on cod 4 its around 2.4 and mw2 its 2.7
so anyway checking my halo 2 stats and im only 1.2 which makes me feel bad, however that only proves to me that in general the playerbase had more skill
What is viewed as an acceptable K/D in online shooters on gamefaqs has steadily increased. This is how you get the incredible situation of somebody describing a 1.5 K/D ratio as that belonging to an "average" player.
Personally, I'd prefer it if people stopped harping on about such a meaningless stat, but that day will never come to pass.
If you can't see that the average K/D doesn't necessarily have to be 1.0, think of a simple example.
Suppose that player A and player B have a 1v1. Player A wins 10-1. Then Player A's K/D for that match was 10, while B's was 0.1. The average of these two is 5.05. If the Halo 4 playerbase was split into two equally sized groups - those with K/D's of 10.00 and those with K/D's of 0.1 - then the average K/D would be 5.05.
A high K/D ratio can indicate anything from "has incredible innate talent" to "mercilessly slaughters thumbless guests and teams of two to pad stats". Don't read too much into it.