What is the importance of the city of Seattle in the book, Flight: A Novel?

The beginning and end of the novel takes place in Seattle in the present day, where Zits lives in the foster care system. For the most part, Zits experiences Seattle to be a cruel and unforgiving place, where money and resources are hoarded by the wealthy, including several of his own foster parents. However, Seattle is ultimately where Zits finds redemption when he is ultimately taken in by a generous foster family.