Most people who defend quickscoping say it was always apart of the game and never show proof, they act as if their word is good enough.
This is for the people who say quickscoping takes skill, well people also said it took skill to BxR, BxB, double shot, triple shot, and quad shot and look at how that ended up. (Talking about Halo 2) it wasn't implemented into Halo 3 because the dev's hated it and so did many of the players because it gave some players an unfair advantage, that is what quickscoping does. It gives the most dedicated an advantage over the ones that do not do it or not willing to give it a go. It doesn't take much effort though to do it in the first place.
I look at quickscoping the same way I'd look at Bhopping, BxR's and Quad shotting, I look at it as an exploit of poor mechanics in a game.
I do enjoy bhopping though, really fun to do, but because I find it fun doesn't mean it was meant to be there nor does it mean it should stay.