I sorta think there is no such thing as quad dominant people.... just people with weak hamstrings and glutes. It seems a strange solution to switch to a movement where the quads can hardly be used to remedy weak hamstrings. Why not just train the hamstrings in knee flexion and hip extension and get them doing the movement well?
I think you have a very solid argument here ^^^, especially if you couple this with tight hip flexors/dormant glutes.
And to answer your question - since I can't do high bar squats and do low bar squats and deadlifts instead, yeah, I'm missing SOME quad activity from my training. But like Lance said, "I'm sure moving the bar 1 inch lower on your back will completely deactivate your quads and they will get weak and small". The point is - the quads still get stimulation from the low bar squats. Especially as I'm a quad dominant guy by nature so... I kind of always call on my quads when doing stuff.
My problem is that I was never able, after years of training, to build my VMOs... and I want HUGE VMOs.