Marc Flandreau, a financial historian, has written on the history of these institutions; their rise to prominence occurred at the junction when the giant balance sheets of the imperial age (Rothschild, Lyon, Bearing etc.) were dying down -- and CRA were supposed to fill the information gap. Only problem - when Rothschild gave a AAA rating on a bond, every other investor knew this was solid because (i) Rothschild would guarantee the price by buying the dip and holding and (ii) Rothschild spoke to management, in that they would "correct" management's strategy.

CRA don't have a balance sheet to absorb these issues, and they don't have a lick of influence on management... "safe assets" are not made, they are engineered.