The Nunchucks get a pretty bad rap from most serious martial artists, and, for years, I included myself in that generalization (being ever so serious myself).
"When am I ever going to have a pair of nunchucks in the real world?" I would say (oh, come on, you've said it too)
The truth of the matter is, you won't. (You'll rarely have time to construct a pair, either... Duct tape and two salmons? Rocks and some twine...?)
However, the principals learned from a nice, safe, padded, foam weapon transfer very, very nicely to a lot of practical and available tools such as chains, heavier ropes, and even more obscure items such as a pillowcase with a can in it.
Understanding the concept of continuous motion, flow, and the theory of a flexible weapon is a wonderful challenge to present to yourself in your continuing development as a martial artist.
While I would still put them on the bottom rung of priorities, I would say to you as a crusty realist that it is worthwhile to put in the occasional training session on the nunchuck.
Here's a step-by-step instructional video on nunchucks to watch in youtube on continuous motion. Make sure you have captions enabled, as they link to the next step in the series.