Disney's produced a very large number of consistently high quality films over the past decades. I don't know if any of the characters or stories came from public domain, I couldn't care less. Their animators did some amazing stuff, the attention to detail and the subtle expressions by the characters. It's so much better than anime crap.
It's one thing to ripoff someone's work and sell a shoddy copy. It's another to turn it into a high-quality production and bring it to millions of people.