Forest fires have zero to do with financial cycles.
What Greenspan was doing, rather successfully, was maybe like pruning back the underbrush.
He was on the right track, but he simply failed to regulate a couple of things that should have been regulated better, or at least get Congress to make the proper moves with regard to requiring insurance that guaranteed the value of bundled mortgages, and restricting Fannie Mae and Freddie Mac from granting mortgages especially ARM's with teaser rates, to people who had no hope of paying them off.
Minor dips in the market will always occur, but major panics are what we need to avoid. It could have been done, but it wasn't. Politicians on both sides are to blame.