Earlier quoted context omitted.
Better bike infrastructure keeps bikes off the sidewalk. As a biker you can't win. Drivers try to run you off the road, pedestrians don't want you on the sidewalk. Bike lanes are a solution, but the political will needs to be there. That being said, in places where bikers feel they have to use the sidewalk, they should absolutely yield to pedestrians.
In places where bikers feel they have to use the sidewalk, they should absolutely walk their bikes. It's what the law says and its very sensible all around. If you have to go the wrong way up a one-way street or if the road is blocked, you can just get off your bike and walk it for a block. It's not the end of the world to have to walk for a minute. As both a biker and a pedestrian in NYC, this seems so glaringly obv…
In many places of the US you have sidewalks built because they were mandated by law but are rarely used.
A typical example will have a 4-lane 45+mph road next to big box retail stores. This type of road is unpleasant to bike on but the adjoining sidewalk is empty and, assuming it has sufficient visibility to allow the cyclist to avoid left and right hooks, is much safer than the road.
NYC is a fascinating and important place but for better or worse is very different from the typical US city.