Not convinced about that statement about average market participants, also define average market participant and explain where the HFT's profits come from if not other participants.
How do you disallow it?
My initial suggestion was to slow down cancellations so that they take substantially longer than a new trade does to pass through the system. My perception is that it might reduce the visible liquidity/availability but not the real liquidity as much of the visible liquidity disappears when someone tries to trade against it.
Another suggestion would be to move to a single exchange