> My first guess would be that cities designed in the automobile era suffer more when they have to sacrifice the already limited pedestrian space they've got.

I think you have the right idea, but maybe turned around: Pre-automobile cities can have narrow streets and cram in space for cars, including driving and parking. Newer cities are built with roads (and sometimes sidewalks) at such capacity that the distance to cross them becomes a pedestrian obstacle - 'pedestrian unfriendly'.

Regardless, the question stands.