I can of see people's point's here..
I guess Pureenimtalis you had a 4-5 KD when you first started because you played demo and beta like me? It's easy to mow down noobs in Recruits anyway.. I used to always come out with 10+ KD in recruits then now (on new account) it hovers around 5.2 KD which is my glass ceiling.
The game is hard for new people, it's very fast and dynamic and requires intelligent use of modules. It's also very hard for new people to see enemies in cloak, my brother had no clue how I could see them. When I first started playing it on the beta I was s**t as you would expect from a newcomer and I had little to no experience with FPS. Something just clicked with Crysis 2, I could do more or less do whatever I could think of and quickly got good. It's been years since I've loved again as much as I did the first few months I had it. Love it now despite the BS!
Compare this with COD, you are always exposed (no cloak), air support kills you all the time, movement speed is slow, weapons kills quicker, weapon imbalances, no defense against grenades (except flak jacket in Black Ops), you have to watch corners and for campers/quickscopers. In MY PERSONAL EXPERIENCE (note the capitals).. COD is alot harder than Crysis and more mentally exhausting to play.
To the OP, just put in the time and enjoy the game. Don't worry about the KD. Do your best and then you can reboot your suit at level 50 and then you should be good and have a higher KD. If you can get 3 KD+ plus then you are better than 80% of the players out there.