In some cases, they ended up standing behind the asset-backed securities they had sponsored, largely to maintain their reputations, despite having no legal obligation to do so.
A policy that, instead, pushes banks across the board to rapidly dispose of NPLs in the market would result in a massive transfer  BIS central bankers’ speeches  1  of wealth from banks to private (speculative) investors that base their choices upon very high risk premiums and related returns.