I hate to say this, but Brooklyn has this reputation of being VERY unfriendly. They never say Good Shabbos unless they know the person. There is no out of town community that behaves like that, and the further you go from Brooklyn, the friendlier they get! I think individual people just have to start being nicer, in order to change Brooklyn’s reputation. Then maybe we can expect Mashiach!
actually, to tell you a story I had over Shabbos while I was in Flatbush, while I was walking home from Hashkama (around 9) and people were going to shul, I said good Shabbos to people as I passed them by, some people didn’t answer me but others did and one person even greeted me before I had a chance to say good Shaabos