Basically, the method was born during world war 2 in the SOE/OSS training courses. The idea behind the method is that it is to teach the agents how to make fast followup shots. They started by teaching them to fire two shots in rapid succession so fast that it seems like they are firing the second round without even aiming. The idea wasn't like it is today where you don't even aim your second shot.
Somehow after all these years, the idea was turned from a training base into a method of engagement. It is annoying when people get attached to shooting two rounds only at each target as if that is the magical number to get someone to go down.
This doesn't have to be a method anymore, and I recommend that it cease to be a method, and rather become a training base once again. Practice this and gradually go up in shot count. Work all the way up to the full magazine. Each shot should be aimed and the sights are supposed to be accounted for at all times. At no point should you be yanking on or jerking the trigger when you intend to break your shot.
Try this a few times and see what you think. I have found it to be quite helpful. You won't exactly be tearing a ragged hole in the middle of your paper target, but you can still make a good fist or hand sized groups which are still really good for shooting fast. Eventually, with a little practice, you will be able to machine gun your pistol and still get good groups. Hope you learned something here and keep it in mind the next time you go to the range.