What you are saying is true for the average ear dog ... who just grabs the ear itself and/or who stands directly in front of the other dog.
However a good ear dog doesn't just grab the ear, and he damned sure doesn't stand directly infront of a dog. Instead, he grabs the whole side of the head, from about 3" above the ear, to about 3" below it, and he absolutely clamps it all together like a vise, getting deep into the flesh of the head. When you face a dog like that, who is athletic and intelligent ... and who places himself perpendicular to the opponent ... especially if he has a HUGE, STRONG neck ... that opponent is never going to get there. I have watched it happen too many times to count.
Please understand that I make a distinction between "a dog on the ear" and a true Ear Specialist
Just think about the fact that a truly good ear dog can control a 200 lb animal with an ear hold, how easy it is for him to control something his own weight.
However, against an average dog "on the ear" I completely understand what you're getting at.
Jack