Hard to tell for many reasons, most of which are stated above. I've been a solid 2k/d player in the last three CODs but this game I hover around 1.5. Pretty sure the difference in my case is a mix of connection issues and added incentive for objective play which makes the pace of games generally faster. I never tried to cap the other teams home flag in Dom on other CODs but now it's pretty tempting. I heard that the official average in COD is around 1 and with skill-based matchmaking that might have even gone down a bit in BO2.
Anything above 1 is good - because on average you're killing people more than you're dying.
That said KD is irrelevant in this game, because skill based matchmaking hasn't worked (surprise surprise) - Most lobbies consist of 1 or 2 players that have a 2+kd, about 6 will have around 1KD then the rest will have below 1 KD... So with such a wide range, this is not skill based matchmaking, and all you're showing with a high KD is that you've taken advantage of the weak skill based matchmaking, and probably only played in lobbies with negative KD players and backed out of any that show a challenge.
That is not true my k/d is 1.54 (370 spm) and I rush, gun's blazing. Occasionally I used to get smashed up a bit but there is a difference between rushing straight into the other spawn, and doing it and figuring out were the campers on the other team are hiding.
I do agree with the fact that the majority of k/d's over 2 are campers though. I would guess that 90% of +2 k/d are campers, maybe more. I have only ever met a cpouple of players with a k/d that high and thought that they were really good.