There will always be situations where you’ll be under the cut point of a low beam. If there’s a small incline then a flat intersection the drivers opposite the incline get the fill low beam. It’s part of what makes HID lighting dangerous to pedestrians. It obscures the vision of oncoming drivers turning left or right. Also if an automatic headlight system doesn’t react to turn the high beams off it will blind people.

Not really. When incandescent headlights are mis-aimed, it is generally not nearly as blinding or painful [for standard car headlights]. Mis-aims happen - it shouldn't be a risk to other drivers when they do.