Yeah, I really don't get what people are on about with this.
Are you guys holding it like this?
Because I hold it like this:
And when I need to press L or R, I do this:
true, though he did say he was putting his middle finger on the top shoulder button, which is even worse than what you have pictured here. Though he probably meant or I hope he meant, middle finger on the triggers. Anyways, I either do this, or keep my trigger finger on the triggers and hit the bottom of the shoulder buttons with the middle inside of my same trigger fingers, by barely lifting them.
edit: also with position 1, it is difficult to press down on the sticks because you dont have enough support /grip on the controller.