There's a difference between stopping to help someone whose gear cr@pped out, versus offering to help someone (still mobile) that just made a poor equipment choice.
I would say that, unless you ask, it's entirely possible that the lightless person was one of those folks whose "gear cr@pped out". Maybe he has a broken LED headlight in his pocket.
I wouldn't help somebody out if they didn't want it, but I wouldn't be too quick to assume things about people who ride bikes in the dark without lights. People have the perception that bikes are sold with reflectors because reflectors work. People who don't ride every day are likely to assume that inconvenience and cost outweigh the benefits of having lights in addition to reflectors for irregular night-time use. Those of us who ride all the time and have regularly heard about, and maybe seen, the results of riding without lighting can't fault everybody else for not knowing what we know.
Although this underscores the fact that I think new bikes should be sold without a front-center reflector, and front reflectors should be sold with a warning that says that "car headlights will rarely light the reflector up enough for it to be of any use, so buy a light or several, okay?"