Sidewalks are for pedestrians, not bicycles

All of the discussion seems to be about cyclists being able to ride more safely on sidewalks than on roads. While that may be true, it needs to be recognized that bicycles on sidewalks are very dangerous for pedestrians.
Sidewalks were designed and built for pedestrians, many of whom are children and seniors. I have found it startling when a bike comes up behind me with no warning.
I am also appalled by the number of cyclists that expect me to get off of the sidewalk so that they can ride by. I