Subject article is great --- comments after it are also worth the read. BTW, we'ed have a lot more interest in commercial activities if we practised the dzamalag ceremonies.
From where I sit, a creditor's ability to collect on a debt is no better than his ability to enforce collection.. which ultimately means some kind of physical coercion to the debtor or their interests. Extending credit is a matter of an assessment of personal trust or having sufficient collateral and control of it so that trust doesn't matter, or superior physical capacity to coerce payment or enslavemnt to pay off the debt.
Defaulting on a mortgage is simply letting the creditor take possension their collateral ... that it might not have been suffficient enough to cover the debt is the creditor's failure, not the debtor's. ... No harm, no foul.