I think we all were, to some degree. Rational minds (and i'm not saying I was one) could have looked at the real estate bubble and availability of credit and personal debt and observed that it was fundamentally unsustainable. If you did not buy a house you couldn't afford, or take on too much unsecured debt, and kept your job skills marketable, chances are the crash and recession have affected you little.
That being said, Wall Street and investment bankers knew what they were doing, and how risky it was, and they knew it wasn't their money they were gambling with (and not just gambling, but roulette odds gambling). Blame has to be squarely given to the banking, housing and investment sectors of the economy who saw the quick buck and nothing else, and acted irresponsibly with that charge.
Lastly, the politicians who repealed Glass-Steagall, being too beholden to the very bankers and investors who would benefit from it, launched caution to the wind. This is both the Clinton and Bush administrations, who let it happen, then short-sightedly took advantage of the boom times and talked of an "ownership society", knowing full well it was a house of cards. By lavishly spending money and extending tax cuts while entering two wars, they destabilized the strength of the US economy and limited our options for dealing with the downturn later on.
Plenty of blame to go around.