they're blinding, preventing oncoming people from being able to see. and because lowbeams are just as bright as highbeams, just aimed lower, even lowbeams blind people. drive anywhere in a hilly area and this becomes apparent.
they're also obscene to be blasting into pedestrian and cyclist eyes in low speed neighbourhoods with streetlights. like how would those drivers feel if I walked around with a 4000lumen flashlight pointed at their eyes as they drive.