You actually have multiple K/D Areas. They all contribute towards your overall K/D Ratio. But K/D Ratio means nothing. And "Being more serious" is exactly what's wrong with Social gametypes these days. Social was never intended for sweaty try hards that care about such things as a K/D Ratio, they were designed for people who were casual gamers, seeking casual games.
Truth be told, unless you're one of the sweaty try hards that are ruining the game for everyone, don't worry about your K/D Ratio, and have fun. Your worth isn't in your independent K/D, but rather in how you help your team to victory.