She beats them in lane 1v1. Which means she auto pushes them in and harasses. Which makes her an easy gank.
There's a reason that Fiora went something like 14/15 in the LCS with Quinn as the predominant counter-pick. And why Quinn's win rate was so low in the LCS.
Quinn is annoying in solo queue because she's a lane bully. She gets outscaled though and is easily gankable.
When are melee top laners going to learn to stop going for every CS and just let themselves fall behind a bit early while they wait for a gank... I say this as someone who also plays J4 and Volibear top lane (in addition to Quinn and Gnar).
My last top lane as J4 v Teemo? Just Cs'd with Q and E as long as I could, rushed Hexdrinker first item, and waited for an opportunity to ult when I received a gank. The playstyle is pretty similar for just about every other melee top laner in a melee v ranged matchup. You LOSE melee v ranged by default 1v1, BUT you scale harder in to teamfights and have a much easier time getting kills from ganks. As long as you're willing to give up CS it should be won lane for you, NOT the ranged champion. The whole reason ranged is strong top lane is because it's a gimmick that solo queue players fall for, over and over.