Greenspan supported the repeal of Glass-Steagall, and also supported the Commodities Futures Modernization Act, which did a huge amount to legitimise Credit Default Swaps.
He opposed HOEPA oversight by the Fed of fraudulent liar's loans by unregulated lenders. He was on the wrong side of multiple conflicts of interest, including some related to Enron's SPV frauds.
While Greenspan was giving PR-scented talks about the renewal of trust in the markets after the regrettable failures of the Enron years, the FBI was warning there was an epidemic of mortgage fraud.
So - no. Greenspan was not a misunderstood and essentially powerless economic moralist. He was at ground zero of the crash, and deserves a significant share of the blame for it.