If you look at Zürich, one thing that stands out is that everything related to school and daycare / day school works a LOT better in Zürich than in surrounding nearby cities and villages, which is probably a boon of having a socialist city government. So for parents it IS attractive to stay in Zürich instead of moving 30 train minutes outside.

Of course not everything is greener in Zürich, but if you need some public services like well organized schools or services for the elderly, Zürich city is really a bit nicer.