I've been playing for 2-3 weeks. I'm rank 8. I would respectfully disagree.
EDIT: That being said, I don't care whether or not they're reset. But there really isn't any point in doing so. (if you're concerned about an accurate representation of your KDR, just look at your recent sessions, not your overall) Actually, if people are seriously concerned with their KDR that may be why we have a retarded shortage of medics.