Because it is a skill that I have worked at and loved since I was a small girl. Probably my best loved activity. No, not probably, it IS my best loved activity. (ummm, okay, in public activity :D).
The most magical, close-knit, “soulmate” type relationship I’ve ever had was with my former SO.
We met at dance class. We honed our dancing skills together and took pleasure in our own skills and the skills of our partner, it was a friendship and partnership within a love relationship. A dance partnership has most, if not all of the same requirements that a love partnership has.
Trust, attraction, communication, and ability to compromise and be there for the other person.
In the best relationships, there is at least ONE common interest among the two people involved. When that common interest happens to be dance, it’s as if the relationship is bigger than life and that every aspect of a normal relationship (trust etc) intensified and made better.
Add in all of the reasons many other posters have stated (such as how willingness to dance and be silly shows such an excellent quality of a man’s personality) and that is close to good “why it’s important to me”.