It is worth noting that the monthly payment is not that different between a 30 and 50, although maybe the difference is enough to make it easier for some people to qualify for loans, and thereby help to prop up the housing market (which presumably is Puilte's objective here).
A $500,000 loan at 6% for 30 years has monthly payment of $2,997.75
A $500,000 loan at 6% for 50 years has monthly payment of $2,632.02
(In contrast, the same loan at 15 years is $4,219.28. And a pure interest only loan would be $2,500 a month).