When the older Disney films were made everyone was racist, most older Disney films weren't racist anyway (Wait, or is not having a token black guy racist?), and the one's that were weren't that bad except Song of the South.
I can perfectly understand why they've waited so long to have a black Princess, just look at all the controversy they've had about Princess and the Frog. Her names too steriotypical, her voice has too much af an accent, she looks too black, she doesn't look black enough, OMFG she's a maid? Evil Disney, EVIL!!11!
They can't do right for doing wrong. Seriously, people are too picky.