Yes, they should...
Hope you recover quickly, Charlotte!
Remember if you see a tall guy in the crowd look twice! He might be running over your feet in the next second, like when he tried to run over my car a few months ago.
People who use these scooters should be told clearly that others won't reflect them as moving around at the first glance, either if they walk or drive a car.
If you see someone running or walking you know immediately this person will move around and your mind will registrate the direction quickly. If you observe a person standing still — as a scooter driver do — you never expect this person will move 10 meters in an eye-blink.
If someone comes running behind you this persons breath and footsteps will warn you. A scooter driver makes no sound to warn you.
This is the same reason animals cross the road and are killed by cars, and sometimes the driver got killed too.