WHAT IS THE FUNCTION OF THE FINANCIAL SECTOR?

I know up to this point in our history, Wall Street, with its big buildings, tough executives, and large buckets of MONEY, has developed a bit of a mystique about it. I don't know what it is, personally; all these people running around, creating, buying and selling all sorts of esoteric financial products, working absurd hours, and making more money than they know what to do with, never really appealed to me. However, in light of these new financial regulations (and more importantly, the entire collapse of our economy), I have more important questions we need to be asking ourselves.

Looking through the "myth of Wall Street," what are banks really supposed to do? Banks and the financial sector in general do not produce anything. They do not contribute to the output of this country; they provide a service, which facilitates the production of goods and services from other parts of our economy. If the financial sector merely serves as a lubricant for the rest of the economy, I have two questions that follow: is it really necessary to save the financial sector in its own right? Is it necessary that banks be run as a private enterprise?