The only controversies I’ve seen regarding bikes I’ve seen as a city dwelling American, are bikes not following the rules of the road.

People get upset when bikes run red lights/stop signs, ride the wrong way on streets or paths, or go way too fast on shared pedestrian paths, especially if they don’t have a bell or horn of some kind.

E bikes get hate because they allow people to do 25 to 40 mph on pedestrian paths (where the speed limit is half of that or less). Where I live, lane splitting for motorcyclists is not legal, but E bikes do it relatively frequently. Motorists are not expecting a tiny, silent vehicle to go flying past their door at 30 mph when they’re stopped. And for some reason, most E bikes I’ve personally seen riding at night have no lights of any kind. I don’t want to hit someone in my car, and I don’t want to be hit by someone as a pedestrian, and it’s a hell of a lot harder to prevent that when you can’t see them.

I ride my bike on shared use paths and the street with lights and a bell. I follow the rules of the road, and I’ve never had any issues.