What is the problem the value of the house or the value of the mortgage!

The banks are holding the mortgage...the home owner is in the house.....the Fed is trying to figure out what to do. What if we just consider the value of the mortgage from a financial asset point of view. As long as the payments are made, the value of the security (the house) doesn't matter does it? So what if the Fed looked at making the payments on the problem mortgages until such time as the asset values increase or the home owner finds other work. The Fed could perhaps develop a model to measure whether the default is the result of poor lending practises or the result of the economic downturn. Let the banks absorb their mistakes and let the Fed help those that truly need and deserve the help. I think that the banks are using this problem to have the American tax payer cover their bad lending decisions and the huge bank bonuses that were paid on them.