Speculation is another word for investment. When the US gov't still believed in capitalism it encouraged people to buy something and sell it later for more money. When enough investors agree that the price of something is below its market value, the crowd runs in one direction and the price goes up precipitously.

Under your economic reform plan would it be OK for airlines to continue to hedge their fuel costs? What about the oil companies themselves? Who gets to pick which companies get to buy futures?

Substitute real estate for oil. As prices went up it should have become more difficult to buy a house, instead the government made it easier to speculate by loosening the money supply (low interest rates, deducting mortgage interest, Fanny and Freddy).

What led to the implosion of the mortgage market was the gov't egging on the investors rather than letting the markets run their course. It's much easier for the gov't bodies to blame the "Speculators" for fucking up the economy instead of their own stupidity.