Why would a ballet company need to sell "Ballet but..."? As Adrants comments, "One of the biggest problems with ballet is it's traditionally classified as a 'high culture' pursuit, which gives the dance some cachet, but also shuts potentially innovative new young audiences out."
If ballet today lacks some of the glamour it had in mid-century America, one reason is that aspirations have changed. "High culture" was once an aspiration in its own right—what middlebrow people wanted to achieve, the better to demonstrate their refinement and "class." Nowadays, people may enjoy high culture pursuits, but those pursuits must find their audiences on their own merits, not on the promise of status transformation. You may "better yourself" by attending ballets, operas, or museum exhibits, but the betterment comes from your genuine psychological reaction to the art, not from the idea that you're the kind of superior person who attends ballets, operas, or museum exhibits instead of rock concerts or movies.