When I'm putting up my hand to block their light and trying to look at the pavement by my wheel, I really don't know for sure if I'm going to hit something else.

GriddleCakes mentioned shaped beams. When I'm in my car and trying to read street signs, sometimes I just can't see them at all -- because my headlights aren't spraying in all directions on low beam. When I was a pizza driver, I often flipped my high beams on for a second or two so I could see them. My helmet light is better at lighting up signs -- street names, roadside signs, whichever -- than my car's low beams because it doesn't have a shaped beam with a cutoff.

That's why I prefer to NOT use it on a MUP, and stick with the B&M generator light instead, aimed below waist level.