Buying and Selling Housing Accounts as a Commodity

What Greenspan (and Paulson) euphemistically call 'mis pricing risk' by the nation's financiers is more aptly described as their collective purchasing of 90% to 100% leveraged commodity accounts.
At the end of the day, homes are a commodity. There are laws regulating the purchase and financing of commodities; there are strict margin requirements and lots of bold print that purchasing a commodity carries a high degree of risk, to wit, you may lose your shirt.
Having thought about this for a moment, the question becomes who in their right mind would set out to purchase someone else's commodity position which had little or no equity, just the position holders' promise to pay interest on the borrowed funds?  
If you are a bank that has access to buyers that accept the premise that housing always increases in value, then by all means, create or buy this type of commodity mortgage account, warehouse them and resell them. It's a business plan. I package and sell, you package and sell, just be mighty careful when the music stops because at that point the bankers own these crap assets that they intended to sell off to others. Merrill Lynch got caught and burned warehousing several billions.
Gold is a commodity which has the flavor of always going up but yet there are margin requirements. Housing, given that the number of buyers always increases and they ain't making any more land you know, seems a sure bet "over time." Near term however it's a commodity, subject to rises and falls due to interest rate changes, recessions, speculative fevers and inflation.
The banks, etc are idiots for placing their firms' equity in jeopardy by creating and holding no equity housing accounts. It's not wholly new however. The banks crashed with excess lending to REITs, Latin America and experienced some hemorrhaging from the tech bubble.
But. And this is a huge but as we head into an election year. Imagine if Mr. Bush had wooed America into placing social security assets into private accounts (because the stock market always goes up ye brethren.)
What would have occurred is that the housing speculation bubble would have lasted considerably longer as Wall St. packaged and sold retail strips of near worthless housing accounts to the nation's social security network.
At least recognize in this last greed driven market bubble or market fever fiasco that the finance industry has wiped out its net worth repeatedly over the last forty years. Keeping Wall Street's mitts off of Social Security should now perhaps be a subject for a constitutional amendment.