Struck me that there is a distinction between people who are into dance music meaning music that is designed primarily for dancing to, and people who dance to the music they like
So for instance, take the historical (possibly ongoing, I wouldn't know) phenomenon of the student indie-disco - this is a case of people who, while professing no interest or indeed rather often absolute antagonism to "dance music", can be found dancing exuberantly to the music they like
In fact most forms of popular music have a dance aspect
Possibly all forms of popular music, in potential (given that the ballad once upon a time would be considered a slowie, for that point in the night when the couples do up-close body to body dancing)
Even metal and hard aggro rock has a dance element, if you count headbanging and moshing as dancing, which I think you should. (Air guitar and air drums etc are also forms of dancing, in a way).
But equally your dance music fanatics who think only the functionalist, purpose-built stuff is proper dance music, you can say, "yes, but look at all these people moving their bodies in patterned ways to music with a beat. You don't own this concept or this practice".
At one point, the concept of 'dance music' as a separate domain from the rest of pop/rock didn't exist, all bands were dance bands - the Beatles, the Stones etc.
Then things got more 'head'-y with pyschedelia, prog etc.
But even then, if you look at the crowd footage of e.g. a Grateful Dead show, the audience is dancing. Indeed there's a distinctive Deadhead dance which no doubt would have appalled contemporaneous fans of Northern Soul or jazz-funk (as would the Deadhead clothing). But it's dancing.
Conversely, I'm sure for some fans of "dance music proper", their enjoyment is bodily inert - largely a cerebral and immobile practice.
