Nobody is questioning the freedom to trade all markets.

However your term "equally" is not what is happening today. When machines are setup to probe and skim all the time and are located in or near the exchanges to leverage latency over somebody on the other side of the country or world that is not allowing equality of trade to all market participants. 

It's much like "free trade" there always seemed to be terms that rig the trade somehow or allows manipulation of one party over the other.  What we need is fair trade not free trade.

Trade all you want but your trades must be transparent and visible to the market long enough to be acted upon. I don't get to forward contract grain for milliseconds then pull the contract back and cancel it to probe where the limits are.