If knowledge suffices then wisdom is worthless
See where this has gotten us. All the very sub-prime awarded mortgages to borrowers that classified as subprime would have not been able to go anywhere had they not been blessed as prime collaterals for other securities.
One reason that stops the world from realizing the foolishness of it all is that the credit rating agencies are private, and we have all been pavloved into establishing a connection between private and free efficient markets. The truth though is that the private credit rating professionals are only outsourced bureaucrats working for some pompous Ministry of Financial Risk Elimination.