There are many people from New York who make fun of people from New Jersey and the state itself. This is mainly because New Jersey is seen as like a dumping ground for NY. There are also many factories, oil refineries, and other poluting facilities in the upper part of central NJ. Most New Yorkers see this part of NJ, so they usually think this is how it is all of the entire state, which is not true. The northern of NJ is very woodsy and on the mountainous side. From central to southern NJ, it various from suburban life to farms.

NJ also used to be a very big resort area. However, over the years, less and less people have been visiting the shores. Cape May, NJ, located in the south at the very tip, is still a very popular and expensive resort area. Actually, many New Yorkers tend to move out of the city to NJ. Many of my neighbors are from NY.

As to why they make fun of people who live in NJ, I have no clue. Example: they make fun of the way they drive. However, when New Yorkers come to NJ, they're awful as well.