the house is in perfect condition, or "turnkey" as is usually described.
i have speculated that the negotiator has only so many people to handle so many properties and so a general guideline of reconsidering a property only so often (once every so many months perhaps) for any modification of sale requirements. and a cash only requirement would eliminate the possibility of an escrow falling out due to a purchaser's funding bank's interference.
and on a side note, a cash only requirement would also significantly reduce the quantity demand, that is, shrink its potential market by making the house unavailable to anyone who would buy it w/ a loan, like me. and thus it follows that a reduction in quantity demand would reduce the effective price. which means at current price it is overvalued and thus the bank has now become a non-serious seller.
if the value of a house is in part created by the demand for it (which it is as is exampled by prices in manhattan and san francisco) then the demand is created in part by the market's ability to buy the house on credit. the latter would increase quantity demand by making the house more accessable to a wider market, thus the price of the house would go up. so it would follow that the price of the house would go down if the ability to buy it on credit were removed.
i could buy it cash at about 9% less than would now be the current close of escrow cost.