Around the Coney Island Area, as displayed above, there are a lot of multi-family buildings. If we refer again to the 11224 zip code data, there are only 1,127 single-family, owner occupied homes in the zip code. In addition, the median family income in the area in 1999 was about 29,000, which is roughly 3/5 of the national average.
This means that the people living near the park are not all ritzy, upscale oceanfront home buyers. A good chunk of them, 16,133 out of 51,205, are actually below the poverty line.
Now, we must take into account that the 11224 zip code also includes the community known as Sea Gate, on the far left of the map above. As you can see, this area is made up largely of one and two-family buildings. Therefore, the area immediately surrounding Coney Island most likely has a higher amount of Multi-family buildings and of poor citizens, than the larger umbrella which includes this richer area.
This correlates with the slow pace of life outside of the Coney Island beach and park, and with the nearly identical clusters of housing projects that can be seen from any point on the beach. The community immediately around the park is simply declining from what it once was, when hotels lined the oceanfront.