"Quick scoping" from what i've seen is for players that have no skill and need to resort to the cheapest way to play the game to win because they cant win playing by the rules.
There is a BF3 multiplayer trailer with actual game footage Here Single Player Footage
Haha, quite the reverse. People who quick scope (especially now) have the skill to hit people fast. I am a personal believer that people who use the FN FAL, M14 and M16 well are the superior players. Anyone get get kills with an automatic weapon, but it's HARD to hit someone with one bullet. What's so easy about only getting one shot off before getting a face full of an automatic's lead? Nothing.
If they bring back quick scoping in MW3, I will be the happiest camper (figuratively) along with the many PC gamers who played CS 1.6 when quick scoping with a Scout was of the most fun game types.
It's not cheat to use, it's not easy to get kills, and it's definitely not cheating or against the rules. Even after post patch in Black Ops, people still do it and are successful at it (cause they are good at it).