Not just handicapped - accessibility features help the able as well. Someone pushing a child stroller, or a grocery trolley. A child on a bike. An adult carrying something heavy.

When people park in such a way as to block the sidewalk, I walk around their car through their yard. If they can help themselves to the sidewalk, I can help myself to their lawn.

And assume their convenience is more important than any imposition they place on others

It has zero to do with that; A bulk of SF was built when cars were enormous. The people parking ON the sidewalk do it because they either don't care, already have a car in their garage or street parking is taken up by people who have 12 people living in their house with 16 cars on the street.

> hardship overhanging the sidewalk imposes on the handicapped

Some of the neighborhoods in question are in off the path areas and on steep grades. I wonder how much this is a legitimate problem or a "gotcha" justification.