The PDF attached to the article, which is a letter SIFMA submitted to Treasury, is a bit more detail, but the article summarizes the big points.
IMO, all of the challenges identified in the article do not require a Herculean effort to resolve except: (a) the policy risk (an ever-changing regulatory environment); (b) uncertainty with how contracts are enforced and who is liable (the letter indicates it will take litigation to settle that)- this includes what should be standard legal proceedings such as foreclosures (is there something "new" in the foreclosure law universe? That process has been around for a long time and should have a small element of uncertainty); and (c) what I would call second-tier jurisdictions who may make claims by way of eminent domain on mortgages (such as municipalities claiming the right to take mortgages as part of their public policy objectives).
The remainder are transparency issues and the assurance that stronger underwriting standards are maintained.
The letter also notes PLS industry can do nothing by itself to change the favorable position that the GSEs have...
(my emphasis)
and the letter then summarizes...
(my emphasis)
So if the private label industry is to expand into the space where the GSEs now dominate, the GSE advantage is going to have to be addressed (which I think is the reason behind the idea of privatizing it).
I spoke to Howard off-forum and he raised what I think is the real elephant in the room: The assurance of liquidity in the mortgage market. Right now, the GSEs are the agency for liquidity and the FED is the bank that makes sure there is a market if all other buyers sit-it-out.
It seems a bit of a chicken-or-egg problem: The PLS market isn't large enough or consists of enough certainty in the rules to grow, and without a larger PLS market, it cannot provide the liquidity that the GSEs do.