This is a topic on free markets...
Those mortgage securities that imploded and took out the financial sector were not a product of unbridled capitalism. The idiots that bought them definitely fell prey to stupidity and greed, but the products existed for an entirely statist reason.
Firstly, banks, mainly national chains, have been pressured, through the CRA and other wonderful legislation, to give loans to members of communities regardless of their ability to pay. If they were found to be "discriminating" against a community by failing to meet a lending quota, they would be black listed. During the Clinton administration, when they were improving these aspects, they added in wonderful things like handing over enforcement to the community organizers. They gave legal standing to community activist groups and other such nuissance entities, the enforcement then went from "if we catch you" to "if they threaten to sue you" and the NINJA loans(again, set up by uncle) flew through the system to avoid black listing.
The GSE's, Fannie and Freddie, were set up earlier in life to create a market for low return lending. A bank, which can't afford to be wasting their capital on something that might go belly up for a 6% return, wont make zero down loans. The standard practice was 20%. You pay 20% up front, and they'll give you a loan. The reasoning being, if you go into default a few months in they've got that 20% cushion in value to take care of their expenses and maybe even make money off the soured deal. Through the GSE's, they negated this problem by purchasing and then repackaging those loans as "guaranteed" securities. The guarantee was the Uncle would bail them out if they went south, which they did, and Uncle did...
A 100% of value mortgage is worth less than it costs. Only that guarantee makes it valuable by negating the risk. It was social engineering, not unbridled capitalism.