I think Tony nails it. The best a photo can do is bring something of interest to an audience who is already interested in the area and has some knowledge. If you have no appreciation of dance, a dance related photo is unlikely to stir much within. On the other hand, if the photo only acts as a reminder of the event for those who were there, it is just a snap-shot.
To put it in other words, there is a certain level of ambition in the audience you are trying to reach. Appealing to the dancer's mother is about as unambitious as you can get... whereas if you want to capture the attention of The Average Man in The Street, you'd be better to forget the dance and just get a pretty naked woman.
The same applies in sport. Motorcycle racing is the one I happen to know best, having been a racer, an official and a spectator:
a) you can show a blurry mess to someone and they'll say "yeah, I was there, just after that Casey did this amazing pass around the outside of Jorge...", the photo triggers memories of stuff that it doesn't show, for a very small audience;
b) you show a knowledgeable person and the reaction is "my god, look at the slip angle on that front tyre, how is he controlling that? And he's already looking 100m down the track at the next corner...";
c) "Wow, he's leaned over a long way, how come he doesn't fall off?"
I'd suggest b) is the greatest challenge and most satisfying for the photographer.