I never saw Kwanza special on TV or the Kwanza tree lighting ceremony so dont think it is as prominent as you think... Call me when there is a Simpsons Kwanza episode
Phantom Fireworks sends me e-mails about their "Celebrate Kwanzaa" specials, buy 1 get 400 free fireworks each year. Of course, they do this for pretty much every day with a capitalized name, like Mothers' Day and Secretary Day. Any excuse to sell more fireworks. So maybe that is not a good measure of prominence.