Just turn the other direction.

Presumably the wind is more likely to blow eastward in Paris, resulting in polluting industries (and working-class accommodation) being placed to the east, while the well-off had the west, and the pattern has replicated itself, outliving deindustrialisation. (There is a similar distribution of wealth in London, which is not far away as far as meteorology goes.)

Look at them from the north looking south and they are.