You said: "In the real world nobody cares about what high school you went to or the neighborhood (island) where you grew up." Whose "real world" is that? To Hawaii "locals" as you call them, it matters. What you are apparently missing is the importance many who grew up in Hawaii place on community and 'ohana. Life here isn't very often about how smart you are, or how rich you are, or what palapala you've got (making it so is a recipe for unhappiness in Hawaii, by the way); life here is about family and community. The questions about "which high school" and/or "which island" are VERY important in this island culture because it IS an island, and we have historically needed commonality, cohesion and community to avoid conflict.
It isn't just Hawaii, either. It's islander thinking. Do you think Nantucket, Jamaica, Sicily or St. Helena welcome "outsiders" who want to change the way they live?
Island "locals" don't like outsiders. Period.
Time to assimilate and accept.