This conclusion doesn't follow from your premises, unless you include the hidden premise that more wealth in the world is the only criterion you're using.
Once you begin looking at things like wealth distribution or the like as measures of "better", your argument doesn't reach that conclusion.
He also implies that the firemen, ambulances drives and nurses who protect a city subject to earthquakes shouldn't live in it (and thereby likely be absent when an earthquake isolates it by knocking down the bridges again).
This conclusion doesn't follow from your premises, unless you include the hidden premise that more wealth in the world is the only criterion you're using.
Once you begin looking at things like wealth distribution or the like as measures of "better", your argument doesn't reach that conclusion.