Similar to many cities having catastrophic fires (New York, Chicago) which allowed them to rebuild their streets on a grid system. Vs Boston, which never had a great fire but which is known today for the phrase "You can't get there from here."
0: https://upload.wikimedia.org/wikipedia/commons/a/a8/1869_Bla...
Somehow they didn't result in exchanging grids for winding streets.
The back bay, though, is newer than other parts of the city and it's a grid.