When you are valuing property with a Positive Economic Model then it cannot predict a future value-it is here, now, today and thus myopic; and, since a bubble has a life of its own, property did not have to be over-valued (pushed by the appraiser) to support high valuations when you had Realtors pushing value, bankers pressuring for value, sales concealing concessions, etc., and therefore, I would say the appraiser was the least of the problem. When the sale price includes a Hummer or world cruise, or the builder paying the first six months of your mortgage, and none of that shows up on the MLS...it's hard to find negatives.
We still have that system. We as appraisers cannot see the forest for all the trees. We will follow the market over the cliff edge because we are not applying the Normative Economic Model... and won't ever be applying it. All appraiser ever said was that this house would bring this much on this day and most times they were right. None of us said this house SHOULD bring this amount and anything more is above the trend line therefore, we are in a bubble until the market decides to revert to the mean. And the bigger the bubble, the reaction is to over-compensate and thus we should then say the value has fell below its mean and is unnecessarily low. That's why with "markets" going up at 5% annually, some REO sales jumped by 40% instead. The REO was undervalued.