Bikes belong on the sidewalk. Sidewalks are dangerous for bicyclists. Most motor vehicle crashes occur at intersections, and sidewalk riding turns every driveway into intersection. Drivers are scanning the roadway, not the sidewalk, for other vehicles. Neither motorists nor sidewalk-riding bicyclists can stop in time to avert a crash.
Bicyclists break laws.
They don't deserve respect. Car drivers break laws too, yet are not held responsible for the behavior of other drivers. All road users are responsible for their own behavior and for sharing the road safely. All road users deserve courtesy and respect from other road users. Bicycling with traffic is dangerous and stupid.