Where Are You Now?

[Jun aka Pekto]

It is actually practiced widely in the US. Was there a left turn signal?

Most probably because they're used to the international traffic law that in the absence of a left turn signal, you can turn left with caution when your light is green...

US driving is on the aggressive end ...

Like here? Yup. When turning left on a green light, cars are often at the middle of the street. If there are breaks in the opposite traffic, I'll cross halfway. If I see there's no way I'll be able to turn left except on a green arrow, I stay put behind the pedestrian lane.