Its not that really. Its like driving a car very sensitive power steering at very high 100 MPH plus speeds. The stiff binding transfers more of your movements directly to the board which makes it very responsive. When you are going fast on a board, all of your body movements have a lot more affect on board performance. So, if you have a fairly soft board; especially torsionally, a stiff binding will make the control very very touchy. It becomes extremely easy to oversteer.
Good explanation. Thank you. Also sent you a PM some time ago - check your inbox