Then the businesses will leave and the local economy will suffer. Those with little will have less. Those with enough to start over elsewhere will leave. This phenomenon is called "blight".
As long as Amazon and MSFT are mixed into the economy, Seattle barely needs luck. Not when it has that much tech cash blowing through it.
That this article is written by someone who isn't from Seattle, and posted by someone on hacker news who isn't from Seattle, really amuses some of us who live on the hill.
Here in Minneapolis the feeling is similar. Suburban and rural folks seem awfully concerned about crime in the city, while those of us who actually live in the city just want the cops’ boots off our damn necks.