Sorry I'm so late to this discussion...to which there is an extremely simple answer. Addressing your quotes above
1. Yes they really believe it because it's true
2. There is not madness involved nor is there an ulterior motive
What you seem to be misunderstanding is that flinching, jerking, or slapping are all correctly addressed through trigger control...what is more accurately called trigger management.
If you can see the trigger dip as each shot is released, that shooter is not pressing the trigger smoothly to the rear until release, but is rather snatching at the trigger to make the shot go off when the sights appear on target...that is a trigger management issue
Maybe we have a different definition of flinching. I'm talking about physically pushing the gun forward and down (and often to the left) in anticipation of recoil. I don't really consider that a trigger control motion but am certainly willing to have it explained to me. In attempting to replicate I have never been able to jerk the trigger hard enough to move the impact point that far.