That makes sense until you assume that bankers have an incentive to lie to each other and to their investors and customers. Information is power, especially when it is strategically withheld from a negotiation. Credit agencies are a form of an attempt at transparency between two or more counter-parties who shouldn't trust each other.  There may be other ways of doing the same thing, but encouraging parties who should not trust each other to so is the purpose that must be fulfilled by any alternative.