You'd be better with reflectors on your lid or jacket so that they can pick up light at any angle where as gloves wouldn't get as much. As this is a bigger area and in line of sight so would work better.
Problem with gloves is there is very little flat surface to bounce the light back. Maybe if the biker had ridden properly or wore better visible gear might of been more productive
I wear a white lid and yellow hi viz vest or jacket for that very reason as on an FJR you like a cop..... makes the buggers look twice
Each to their own at end of the day