this NYTimes site didn't come up.
The last preservation conference I went to had a very good presentation of these houses. The biggest issue seems to be that the land is so valuable and the houses so undervalued - ugly, 'old fashioned' (!), too little - not easily recognized status symbols - that families who own these houses and can't use them have to sell the houses to people who do not care about what they own, just what they can build on the land. Then the character and privacy of the whole low rise neighborhood is destroyed by these 3 story mansions peering down on everyone else - so other people sell too.
I would have liked to see the pictures, but didn't want to spend money. However, I'm not blaming the NYTImes for asking me to pay to view.