Sidewalks have to be usable by people who can't hear, people moving slowly, kids, older people etc. If a cyclist is on a sidewalk and can't safely pass without the pedestrian reacting instantly, they're the one creating the problem
There are people on bikes that ride like an asshole. There are people on cars that drive like an asshole. Both cause (different levels of) risk for pedestrians. There's only so much we can do about assholes, social ostracism works only so far and social change is much harder to accomplish than modifying our built environment to reduce or eliminate conflict points.
As an aside, I've noticed people get startled when I'm on my bike stopped but balancing on my bike while I wait for then to cross. I think some people intuitively model bikes on the same category as cars, so being anywhere close causes them to react as if a car hard crept close.
In my experience as a pedestrian, bikes are worse than cars. Less predictable, less observant of laws, and more willing to take risks that depend on others jumping out of their way.
On the plus side, they don’t weigh 3000lbs.
Bicycles belong on the streets. (I bike to work most days, I take the streets)
FWIW, I live in Seattle, a famously bike-friendly city. Stop signs, red lights, pedestrians and even one-way street signs don’t seem to exist in the visual field of many cyclists here.
Obviously there are reasonable law-abiding bicyclists out there. Certainly all the cyclists online say they obey all the laws. But apparently I’m seeing an entirely different group of people in the real world, zooming around lawlessly.
Motorists exceed the speed limit, roll through stop signs, and are looking at their phones while driving.
Cyclists blow through stop signs, and take advantage of shortcuts.
Pedestrians "jaywalk." There's not much else they can do.
No. It signals cyclists not giving a fuck about the law. In at least some EU countries, it is illegal to cycle on sidewalks, except with children.