On moral hazards
That this could imply the moral hazard of allowing some guilty and bad intentioned borrowers to benefit? Absolutely, exactly in the same way that moral hazard exists when bailing out investors. The final question, as always, is just what side of the equation you most need (or want) to benefit, the debtor or the investor.
To do nothing then?... and have the housing market crash, which could of course help some youngster to at last afford buying a house, but make it harder for other youngster to find a job. You see? It is not easy, even for politicians, as life is only about a continuous choice among so many different moral hazards.