Other than our preconceived notions from its sordid past that kindergartners shouldn’t have, what makes it inappropriate?
I’m pretty sure the dancer wasn’t flinging her top off halfway through the routine or humping the pole or anything like that. For the kids it’s just an especially athletic and impressive form of dance.
Or maybe people are worried that the kids will become interested in it for the dance and cause embarrassment for the parents when they ask to take a class but all of the classes are offered by and for strippers?