We don't know enough about it. If it's only thing is the removal of bending, then yeah it's a blunder of a theory. However if energy bending is instead just incredibly difficult (as well as there's NO ONE to teach it) then it's possible it could be used to manipulate another person exactly like blood bending. As, when we later find out he's a blood bender, we also learn that a subset of the subset blood bending is the ability to wipe out someone's bending. So I personally believe non-canonically that blood bending and energy bending are separated by the distance that mud/slush bending is to earth and water. We just don't see enough of it. Also does it EVER explain how Amon just stumbles onto the ability? He tells Yakone that the Avatar is the most powerful bender since he took his father's bending away. Also is there a blood bending Avatar possibly? Aang never learns the skill or how to counter it (dumb as it's used to almost kill him twice) yet when he Avatar states, he's un-blood bent? I know he's accumulating all the past avatar lives when he flicks the switch, so why would he suddenly be okay then... some past Avatar knew about blood bending and how to fix themselves around it