Yes, Redhead, you caught us out. Most of us who've posted in this thread are recreational riders. Without going back through, I believe there were a couple of randonneurs who posted, so I don't know why they forgot to list their lights!

I, and at least half of the roadies I ride with, do have taillights zip-tied to our seat packs, since evening rides usually wind up at dusk, and winter morning rides can begin before it's fully light. I use a truly blinding taillight, actually, in addition to wearing only high-visibility jerseys and jackets day or night.

I do ride my commuter bike for SHORT rides at night (under three miles), mostly on MUPs and VERY low traffic low speed streets. On that bike I have a pro forma headlight plus a nice bright taillight. The headlight is more of a marker light - enough to be seen by low speed traffic, enough to keep me from getting pulled over by the cops, not enough to illuminate the road ahead very usefully or to be seen on higher speed roads. It's enough for the riding I do on that bike.

But there are much, much better headlights that are definitely a necessity for "real" night riding. Do a search or just browse through the commuter section here, and you'll find discussions about lighting.