Greenspan made disastrous monetary errors in the 90’s and 2000’s that contributed mightily to where we are today. The fiscal/regulatory mistakes belonged to the politicians as you mention.
From Justin Martin's book, pg. 205 (early 1994) ... Greenspan: "If you wait to see the eyes of inflation, then it's too late." Martin : "Thus began Greenspan's preemptive strike on inflation, one of the most controversial of the chairman's many policy prwescriptions."
Then, Martin on page 213 writes: "Viewed through the lens of history, the preemptive strike helped set the stage for the most explosive boom the Untied States had ever seen. Greenspan and his colleagues at the Fed would eventually feel vindicated."