Its done only by pros, you wont see any noobs running around being successful quickscopers. You still need to aim, even if the aim assist is pretty aggressive. And if you miss one shot, you are dead 90% of the times. And of course you need good timing. There is no luck, only lots of practise.
Nobody here is trying to make qs'ing a big deal, but its not like its super easy either. And its MUCH harder than running around with fully automatics and spraying from the hip like most people do nowadays.
