Commenting on Dumbo in the last of 25 “mosaics” on the film, Mark Mayerson notes:
Having watched this film over an extended period of time, the thing that strikes me most is how the main characters of the early Disney features are so passive and so victimized. Snow White does nothing on her own behalf except decide to become a housekeeper for the dwarfs. Pinocchio takes no positive action until he decides to save Gepetto. Dumbo's only positive action is to fly without the magic feather. Bambi goes with the flow until he fights another stag for Faline.
A character's arc implies growth towards a new viewpoint, but in the early Disney films it's like there's a binary switch that gets hit as the climax approaches. The characters don't grow towards maturity, they achieve it in an instant (and in Snow White's case, not at all). While heroes generally have mentors to guide them, in Dumbo the mentors are just about the whole show.
. . .
This lack of personality, except in the most general terms, may be a reason for the film's success. Dumbo is a blank slate that the audience can write on with their own feelings of victimization. During the depression, there was no shortage of those feelings.
The recurrence of helpless heroes and savvy mentors may say something about Walt Disney himself and may mesh with the zeitgeist of the time. Walt had an older brother who looked out for him and stuck by him as he tried all sorts of questionable schemes and fell victim to a series of predatory businessmen like Charles Mintz, Pat Powers and Harry Cohen. That's practically a blueprint for Pinocchio, and Pinocchio taking responsibility for his actions may correlate to Disney taking ownership of his creations.