A certain amount of "visibility" problems are cause by drivers too, if they are too close to the car in front then they lose peripheral vision, or they're driving too fast or some combination of the two.

Sure a rider dressed completely in black at night will be hard to see, but if you can't see a cyclist in front of you in broad daylight and have enough time to react to them then you're either driving dangerously or you're eyesight isn't good enough to be driving.