First - is this criticism appropriate just for ballet? Has Ms. Kaufman also peered into the orchestra pit to check the race of each member of the orchestra? The stage crews? The lighting crews? Does this only apply to the performers on stage?
Second - why does she only mention African Americans? Most ballet companies in the United States do have a variety of minorities, but not all of them are African American. Indeed, in many of the regions represented in "Ballet Across America", the other minorities (hispanic, northern asian, southeast asian, etc) are much larger minority populations than African American populations. I believe this is a blind spot for many Americans, and not just about Ballet. They think "minority" and instantly think African American, and the Asian or Hispanic soloist on stage is somehow invisible to how they perceive the company's make up.
Third - as has been mentioned before, ballet was invented in Europe, most of the dance schools are in Europe or European-American dominated cities in North and South America, and it's not really a surprise that the majority of dancers come from those backgrounds. If she reviews Alvin Ailey's troupe, will she say they need more white people? What would she say about the dominating Asian American troups on "America's Best Dance Crew"? (My guilty pleasure TV show)
Fourth - Like it or not, in North America you need parents with adequate income to fund a ballet education at a high training level, or an interested financial sponsor who can fill the void. That excludes a lot of talented kids of all races, who pursue other cheaper dance forms in public schools or private groups.