Koreans do not really make eye contact. Is that because thay are not friendly? I live in NYC. Its the same here. Is it considered rude?

It’s more of a cultural thing. I had hard time adjusting myself making eye contact when having conversations when I first moved to America. 
Looking directly at other person’s eyes is considered rude or disrespect in Korea. Especially if they are older or have higher rank than you. So when parents/teachers talk to a kid, especially when the kid is in trouble, looking directly at the elders or making eye contact is an act of defiance – now the kid is in bigger trouble lol.
So if we don’t make eye contact, it’s not always because we are rude. On the contrary, some Koreans feel weirded out when others look directly at their eyes and talk because they are just not used to it!