i dont think so....there's too many factors going on in the game (specials, characters, teammates, objectives, etc.) to solely say k/d determines skills....also, you can kinda 'protect' your k/d if just camp for kills and don't do objectives.....the only pvp game mode where you might be able to say k/d ratio = skills is rumble, and that's cause it's you vs everyone and the objective is to kill....
to me: the only way i think you can determine if someone has skills at a game is to play with them and/or see footage of them play....