BAB - your points do deserve credit and in an ideal world where if humans were able to detach emotions maybe you have a case. The cold harsh reality of the fact is that you are not an indication of the general consensus of the populous.
When most people see the house they scrimped and scraped for and are doing without other things for drop in value without any idea how long before it is back in positive territory, it WILL have a psychological affect on them - it may even stir up reckless thoughts about how to get out of the situation. As these people talk to each other a herd mentality develops and eventually something occurs - a stampede.
People are talking to each other right now about it and if for any reason prices drop further or the debt burden worsens, or both (most likely because of interest rates, higher taxation, pay cuts, job losses, wages not keeping up with inflation etc.) .. watch out for the stampede.