To understand this, you have to understand who Mel Watt is. A former congressman from Durham, NC, ie black, he is a far left ideologue. He has zero experience in housing or banking, and is basically just another radical black obama has put into a position of considerable authority.
Watt's imperative is not to enrich lenders. It is ludicrous to even suggest it. He wants to get back to shoving tons of money to obama voters to go along with their free health care and obama phones. Get them that obama mortgage as well.
The 5% down payment standard for "certain", ie minority and illegal immigrant, buyers was irresponsible enough to begin with. Take buyers with the worst credit and most incentive to default and put them in a mortgage with essentially no down payment. What could possibly go wrong? So now it is 3%.
Radicals like Watt consider this to be the essence of fairness. Rich white people are making money off the Fed's zero interest rate policy, and it is unfair blacks aren't too, just because they have no assets, no income and bad credit.
Perhaps the other changes were meant to compensate lenders for the inevitable losses on these borrowers. Have lenders already forgotten the extortion suits for "predatory" lending? Now they are going right back to that well. Idiots.
The problem with the housing market had nothing to do with down payments. It was that people with essentially OK credit, but an incomplete credit file, say a short job history, couldn't even refi loans they were up to date on. This forced them to pay much higher than market interest rates, in effect nullifying what the Fed was trying to do. Lenders were reluctant to lend, not out of some grand conspiracy, but because they had been burned repeatedly by the gSE's on less than perfect loans.