Yes, which is why I think jumbo mortgages are going to be the first crack in the wall which brings the whole thing down (although I think "the whole thing" is much MUCH smaller than '08/'09). For regular mortgages, banks can get insurance/guarantees from Fannie/Freddie, so they don't have to do nearly as much due diligence. The risk is shifted off their books to the GSEs and ultimately to us the taxpayers.
For a jumbo mortgage, the people who ultimately purchase the loan don't have that guarantee and they have to put more consideration into the risks involved over a 30 year payback period, which is why those mortgages tend to require more documentation and lower loan to value ratios. If 16 years from now there is a decision made to end federal subsidies for flood insurance (a lot can happen in four presidential elections and eight congressional elections) and, 17 years from now, the mansion someone took out a mortgage on is wiped out, the person who bought the jumbo mortgage, or the private sector guaranteer if there is one, could end up with a very big loss.
I don't know if the GSEs even could start considering geographic factors in which mortgages they will or won't buy or guarantee, but even if they could, they have a big incentive not to alienate a bunch of people on the coasts of populous states by making their homes harder to resell and worth less. Best not to poke the sleeping bear of congress (which ultimately backstops the GSEs and makes their business model possible). Private sector banks/investors behind jumbo loans also don't have to worry about political consequences to the same extent if they decide that survival/insurability/resaleability of houses certain parts of the country are too uncertain to treat those houses as collateral for a loan that won't be paid off until the second half of the 21st century.
*And unlike the 2008/9 crash, because the losses wouldn't hit the whole economy at once, there would be less likelihood the federal government steps in to bail things out, so moral hazard isn't at play to the same extent.