This is a misstatement. Nobody is trying to stop the spread, they're trying to slow it within a bubble. The surrounding counties, cities, and states aren't under quarantine. The bay area is simply hitting the pause button, with a slight rewind, for three weeks. Once those three weeks pass, the pause button is released.
One thing is for sure, unless there's some compensation or forgiveness of late payments/credit score hits from the state, this is going to really harm the lives of those already struggling to afford the bay area.