I would suggest it is odd to claim that the collapse in asset prices were ultimately related to money supply (proximally, maybe - but ultimately seems untenable) - in the sense that asset prices were clearly way way above norms
I do not think it odd. Perhaps it is my orientation. I see prices as primarily a function of cost of production and secondarily (especially true of high-priced items that are purchased with credit) a function of the availability and cost of the funds. Certainly there are other factors with psychology (herd movement) a tertiary factor. Perhaps, you attribute the decline to the herd. If the collapse in prices is not a function of monetary policy, then what is the cause? (I suppose one could argue that it is just part of the "ultimate" business cycle playing out after long being controlled - we lost control of it.)
Your willingness to indite Greenspan for "causing a bigger bubble in realestate" suggests to me that you do believe that money supply and keeping interest rates low did raise RE prices. (If I am misstating your view it is not intentional.) I admit that AG did provide liquidity and lower rates. In my view that would/did raise asset values.
I do question your assertion that "asset prices were clearly way way above norms" in the sense that it is without contextual reference to the credit markets (availability and cost ie interest rates). That asset prices broadly collapsed does say they were too high. But why? A bubble? Ok, but does calling it a bubble explain it? My explanation is that availability of credit and the interest rates are influential in setting asset prices.
Perhaps I should settle for your accepting proximate causation. I do accept that "ultimately" we have some big issues to address. But crashing credit markets would not be in my play book.
Bank lending continues to decline - dropping again in the latest two weeks reporting.*
It is still not clear to me how we can employ our working age population with a low-credit solution. It will soon become obvious to all that slow economic growth will not provide the tax revenues that are required to maintain governmental services of state, local or federal systems.
AI
I do accept that "ultimately" we have some big issues to address. But crashing credit markets would not be in my play book. 
