The answer to your question is in the Greenspan apology.

These idiot right wing ideologues who think the invisible hand of the free market can look after everything.

It never works in the financial sector.

The short to medium term commissions / bonuses /options etc lure for the people in charge means that long term stability issues get lost unless the regulators are tough and think only of what is sustainable for the long term.
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To claw back some of the inappropriate gains of those who gained form the the boom and left younger generations with a huge bill, I would raise taxes on those with high income in retirement( eg raise the income tax on income over $150K) and the rate of inheritance tax on major bequests.