How are players in rank worse than quick play?

I've pretty much used season 0 and 1.0 to learn cloak (and sometimes rocket) before ever entering rank play. I'm leveling pretty easily but I'm also shocked at just how bad everyone in rank is (leveled from silver to gold 1 yesterday). How are some of them even making it to Silver 1? LOL. I've had way more competent play out of QP on the regular. Does it get better at platinum?