The Fed failed to pull the punch bowl away as the party was getting started during the RE/credit bubble. With ballooning fiscal deficits as the result of two wars, the aftershock of 9/11 in the financial markets, the aftermath of the dot com bubble crash, the employment and wealth created in the construction & RE industries, the need for national income growth to cover en lement spending, pressure from Wall Street, White House, Capitol Hill, the "financial media", Main Street (401(k)s and IRAs) etc....the Fed obeyed.
Americans seek a villain, but in many respects it is he who each of us see in the mirror every morning. We expect the government to "do something" about the economy and employment. We've gotten what we asked for. Of course, it makes for better copy to blame the "greedy" on Wall Street rather than the greedy on Main Street.