OK, enough of my critical thinking disclaimer.
I disagree. The point of the left hand is not to counteract the shutter release, it's to offer additional stability completely separate from the shutter. Pressing the shutter is not causing much pressure because the same hand that's pressing the shutter is also holding onto the grip. This can be more of a concern if you're using a tripod and your finger pressing the shutter is the only contact you're having with the camera.
I do agree about thinking of it like a tripod - but you're looking at it upside-down, think about the legs, not the head: with a tripod, you get the most stability with the legs far apart. Same thing with where you hold the camera - the farther apart, the better.