I see a few folks early in the morning riding on the road without any lights and dressed in darker clothing. I shake my head, cuz I have trouble seeing them. But then again, I see motorists driving around at around the same time without their full lights on. This morning at a stop light I shone my light at one such motorist to get his attention to tell him that his tail lights were not on. He didn't bother to roll down window to hear what I was saying. My guess is he probably knew his tail light was out.
So, yeah, lots of dum dums out there. Some on two wheels, some on four, and some on no wheels.