There's nothing wrong with riding in the dark. There are some routes that I avoid after dark, but this is mainly due to my own levels of skill and confidence. Anyone who lives in northern (or far southern) latitudes and wants to ride outdoors year round will probably, at some point, be riding in the dark.
Plenty of people initially think I'm nuts not only for riding at night, but for riding on actual roads with actual cars. These are generally people who do not ride at all, or only ride on rails-to-trails type setups. I show them my lighting setup, explain that it looks more frightening from the perspective of a car, and that usually sets them straight.
If you really want to freak out your well-meaning co-workers and family members, tell them about randonneuring. The Minnesota Randonneurs have one called the Golden Pancake 200 - it's a 200K that *starts* at 8PM and goes overnight.