People who go Quinn top - or any other ADC top - have no confidence in their ability to trade in lane using a proper top laner so they think that being ranged will help them. It's really testament to how bad you are and how little you understand this game.
The incredibly obvious reasons include:
a) ADC champions bring no utility. Can't tank, can't CC effectively, need peel/can't peel... the list goes on.
b) Your team already has another ADC - this is almost as bad as the Support who thinks they need to be APC.
c) Your lane counterpart - if they have chosen an appropriate top laner - is actually designed to negate you later in the game.
d) If you get lucky and your opponent is a complete knob like yourself, you may well carry the game. Otherwise, they will just ward, give up some CS, wait for ganks and you will be stuffed.
Basically, mid-game scenario looks something like that.
Maokai - Boots, ROA and Chainmail
You - Boots, BOTRK or IE or Phantom Dancer (or anything else stupid)
Maokai comes along. Slaps you around or kills you. Has excellent sustain, takes over lane. You're useless. Don't even mention teamfights. You do even worse.
I used Maokai as an example to be kind.