If I can save myself £50,000 on a house purchase by being nasty (at least in the view of the prospective vendor) then so be it.
When selling my house I had to accept an offer well below the price the agent had suggested. What choice do I have but to pass the problem down the line to my vendor? Sometimes the price is the only feature that tells two houses apart
I have found some vendors seem to over-estimate the particular virtues of their house while at the same time being blind to any vices. There is a strict limit to how much "lovely views to the rear" can compensate for a tiny back garden or a noisy location or a 20 minute drive to the nearest shop!