Whenever someone gets upset about small studio animators making a knock-off of a Disney film, I just ask them, "Well, what about the Lion King?"
And then I tell them about Kimba: The White Lion, and how the Lion King is a rip-off of an anime.
Thereafter, I ask the following question: how many Disney movies are actually based on stories in the public domain?
Why get upset at small studio animators who also make movies based on stories in the public domain?