I would not say that realtors and appraisers preyed on people. As for the the appraisers, they are just reporting the current market value of the house. Listing realtors are trying to get the most for their client and buyer’s agents are (hopefully) trying to get the best deal. The market is set by the buyers. It is the buyers, as a group of sheeple, who are responsible. Everyone else is along for the ride. Don’t get me wrong, there are plenty of shady realtors who spout all kinds of rosy nonsense to stupid buyers who believe it. To say that realtors and appraisers preyed on people suggests that they KNEW prices were not supportable. I would say most of them thought that prices would actually go up forever as they are no smarter than the average buyer (plus, they actually believe NAR).
I do think that lenders have failed in their responsibility to the buyers in the last few years. Most people do not really understand the complexities of their loans. They simply do not understand the financial ramifications of their loan outside of how much it will cost each month (and sometimes even that they don’t understand because of ARMs and IO). Fees are often hard to determine, even for people who understand finance. So you end up with too many people in dangerous loans and who do not even understand the perilousness of their position.