I think "frustrating" is the key word here. My subjective impression is that in the US drivers hate slowing down for bikes more than they hate slowing down for

I think "frustrating" is the key word here. My subjective impression is that in the US drivers hate slowing down for bikes more than they hate slowing down for something else, like a car parking or a garbage truck. I think the perception that bikes are dangerous and slow down traffic exceeds the reality. It's about culture, the feeling that bikes don't belong in the road and shouldn't be accommodated in any way.