When Lynn Ellsworth moved to New York in the 1970s, before she went on to get a doctorate in economics, she lived in a boardinghouse on the Upper West Side, with a dozen or so young women who were students at Barnard and Parsons. The system was vibrant and efficient; this was high-density living in a low-density neighborhood. At some point during more recent years, the buildings on her old block in the West 80s were converted into single-family townhouses. In the intervening period, during the 1990s, Ms. Ellsworth moved to TriBeCa, where the frenetically paced construction of expensive high-rise condominiums — high-density urbanism of a far less romantic kind — has been troublesome and disorienting.

While the laws of supply and demand ought to dictate that vertical building leads to more reasonably priced housing, in TriBeCa and elsewhere in the city, the construction and sale of $20 million apartments seems simply to result in the construction and sale of more $20 million apartments. A few years ago, Ms. Ellsworth formed a neighborhood group called Tribeca Trust, aimed in part at ensuring that new residential buildings going up accommodate history rather than subsume it. In recent months she has cultivated relationships with more than 60 other neighborhood groups across the city to form an alliance called New Yorkers for a Human-Scale City with the goal of ending “the violence that real estate developers have inflicted on our skyline, parks, public areas and cityscape,” as the website informs us.

To what extent is it fair to lay blame for this disruption at the feet of Bill de Blasio? Much of what is happening in TriBeCa specifically is the consequence of Bloomberg-era deals and policies. But the perception that the current mayor too easily capitulates to real estate interests, that he cares little about the hazards of extreme density and lacks any vision for urban planning, is very real. This line of thinking certainly didn’t lose credibility after a report in The New York Times last week indicating that the mayor’s Campaign for One New York, which has given money to private consultants who advise Mr. de Blasio, received over $1 million from the real estate industry.

News of the formation of New Yorkers for a Human-Scale City arrives at a moment when the mayor’s approval ratings are strikingly low. A Quinnipiac poll released late last month indicated that only 45 percent of New York City voters approved of the job he was doing. Another poll, released last week, conducted by Marist College, The Wall Street Journal and NBC4 New York, gave the mayor his lowest ratings to date, indicating that only 38 percent had a favorable view of his performance. When Mr. de Blasio’s dissenters talk about an erosion of the quality of life in New York, they are in many cases talking about the cascade of problems that aggressive development and gentrification bring.