Wikipedia:

Moses asked the city to transfer its land along the Coney Island waterfront to the Parks Department. The city granted him that request in 1949.

Moses then had the land rezoned for residential use, with a stipulation that the complex must include low-income housing. He ultimately planned for "about a third" of attractions along Surf Avenue, one block north of the beach, to be demolished and replaced with housing.  Moses moved the boardwalk back from the beach several yards, demolishing many structures, including the city's municipal bath house. He would later demolish several blocks of amusements as well.

City Planners of the era must have hated things like the Luna attraction. Garish, pointless, and so (shudder) individualistic.