2 million people showed their support on a cold winter day last February, most missing work or school. How's that for a fanbase?
You can't control who other people sell their tickets to, and since NY is the biggest market, it's safe to say the percentage of people from other cities, states, countries living in the NYC area are greater than in most other markets. You can't label an entire fanbase because some people sold their tickets to the wrong color jersey. They own the tickets and it's their right to do whatever they want with them.