How is the setting of "Greasy Lake" perfect for this grim story?

The setting of "Greasy Lake" is very important to this story.  The lake in the story used to be very pristeen and was given an Indian name for pure or clear water.  However, the lake is now loaded with trash and is a gathering place for degenerates and troublemakers.  It has become a place that is no longer beautiful and pristeen.  It is now a murky, trashy, foul-smelling lake.  Clearly, the horrible events of the night of the story wouldn't have taken place at a very clean, beautiful site.  Because it takes place at night, as well, is of great importance.  These events wouldn't have occurred if it had been daytime, for example.