Job Itzkowitz, who runs the Old City District, told me he was baffled by the developer’s thinking. “This is the biggest park project in the city,” he said. “It should be more dense.” Only a block away, in Society Hill, another developer has proposed a 31-story tower, 1 Dock Street. It’s odd for two developers to see the market so differently. Ironically, the same developer, U.S. Construction, is now considering adding apartments to a townhouse development it plans to build on the Delaware in South Philadelphia.