The quote below seems to indicate pretty good reasons for the "Why", and even points to a specific problem unique to the target market.
So no, the bailouts were not intended to return us to irresponsible lending, or irresponsible borrowing.
“The banks aren’t losing as much money as they were three years ago, but they’re still losing more money than they were five years ago,” he explained.
Another impediment to lending on go-fast boats? Historically speaking, they make poor collateral for financial institutions, thanks to unscrupulous owners who, when facing default, strip the boats of their engines—and sell them—prior to repossession.
The primary finance options for go-fast boat buyers, Patanaude said, remain home equity loans and loans secured against investment portfolios. But for buyers without those options, finding financing remains difficult at best, and while most estimates range from 18 to 24 months, no one can say with certainty when the credit crunch will begin to ease.