Lenders have no incentive to re-write mortgages. The mortgages were sold to others, then others, then packaged with other sub-prime mortgages and sold again. The holders are many times non-lending subsidiaries created as investment companies. The people being bailed out are the big lenders holding them in subsidiaries because they are still part of consolidated balance sheets and P&Ls.
The mortgages would have to be bought by lenders. Who is going to do that? A new mortgage, paying off the old and starting new, would only be done for credit-worthy borrowers. The lender, once again, has no interest in the old mortgage, so no incentive.
The Fed and government only care about the big lenders with exposure. The property or borrower is not even considered, except for political media consumption.
The incentive will come when loans default. Large packages of loans will be sold off with deep discounts and the deep-pocketed buyers can then re-sell the property or refinance with some new mechanism devised by their government brethren that will insure the lender. Even if the property drops 25% in value, the new lenders will make a killing.
Again, the borrower is insignificant. I don't get this preoccupation with the borrower getting some kind of bailout. The lenders will get bailed out. They are the ones who took the risks, not the borrower.