I wish this were the law everywhere. It varies by jurisdiction. "Each city in California has its own rules about riding a bicycle on the sidewalk. Some cities allow sidewalk riding, some don’t. Check with your city’s municipal code." (http://la-bike.org/resources/california-bicycle-laws)
Assuming you mean where it is an offence to ride on the sidewalk, I'll always choose angry peds or a penalty over getting killed by a coffee-drinking, cell-phone talking urbanite in their range rover. Or non observant lorry driver. Or bus running a red light. Etc.
Cycle a bit in a city and you'll change your view.
Cycling on sidewalks feels safer, but it's actually more dangerous. [1] The problem is that cars don't expect something moving quickly on the sidewalk, and so hit cyclists at driveways and intersections.
There are places that are shared pedestrian/bike paths. The east side of the GG Bridge when the west side is closed for instance. In those cases I think pedestrians should at least be aware of cyclists, instead of walking 4 abreast and blocking the entire way.
I don't own a car and ride almost everywhere. In all the cities I've lived, my experience has been the exact opposite. Since the majority of accidents involve intersections, riding on the sidewalk doesn't do much other than put you in a less visible position, where drivers don't expect you to be and won't be looking for you.
Don't give me that crap. I can't count the number of times I've been nearly run over by cars who refuse to give me my right of way and try every possible trajectory just so they won't be in any way impacted by a person on a bicycle. The only good part about riding on the road is the satisfaction from hearing the honks of asshole cars. I'm taking my right of way and we're paying with our lives if we have to. Fuck cars.
And before you start saying I'll be endangering pedestrians with the same outlook - no. Pedestrians have the ultimate right of way. If there are 8 walking abreast and don't make way when I ring, then so be it, I'll go at 2kph until it's safe to pass them. I'm not in a hurry.