The problem is that pedestrians on a sidewalk do not follow traffic rules. They don't signal turns or stopping in advance. They choose random sides of the sid

The problem is that pedestrians on a sidewalk do not follow traffic rules. They don't signal turns or stopping in advance. They choose random sides of the sidewalk to walk on. They don't have mirrors to see approaching cyclists behind them. Vehicles, on the other hand, do follow traffic rules with regards to lane usage, signaling, and checking what's behind them. Even if they don't, they're still more predictable compared to pedestrians.