All I can say is, they complained that all the princesses were caucasian, and once they made an Amfrican American princess, they had to treat her with kid gloves. I mean, really? The Princesses all had some big struggle somehow or another... Cinderella and Snow White had abusive families, Belle was ostracized for being bookish, Pocahontas had to suffer major historical inaccuracies... And yes, most of the Princesses where white... why? because most of these fairy tales were European. The princesses only started showing signs of ethnicity when they moved away from Europe, and did Middle Eastern and Chinese stories. There are plenty of wonderful African tales that could have worked much, much better. I'd kill to see Disney do an Ananzi the Spider movie.
That said:
Pretty much the reason why they had to move back to princesses, isn't it? After a while, Disney was getting bemoaned by critics for doing princess movies, and once they moved out of it, they got berated for notdoing Princess films. I think that Lilo and Stitch was their only non-Princess hit. Atlantis didn't do too well, and the rest of them tanked...(Treasure Planet was a terrible idea). I still think Brother Bear is a billion times better than Pocahontas, though.