They failed, miserably.

They failed to deliver the one thing people expect from them, which is an accurate assesment of the risk/worthiness of an asset/bond/security. The fact that they gave AAA rating to securities that included sub-prime mortgages means that they were either

(a) grossly incompetent

or

(b) fraudulent.

Neither of those two options paint the picture of a company anyone wants to do business with or take advice from. So, why are they still in business? Why does anyone follow what they have to say about the credit-worthiness of any asset, company, or country?

We don't have to shut them down by executive or legislative fiat. We should just stop taking into account what these incompetents-or-fraudsters have to say about anything.