Ah - there's a book
about the marginalization of accents in American culture. It cites Disney as a cultural reinforcer.
"For the second edition of EWA, Lippi-Green has added 14 more films to her analysis of how SLI is manipulated in Disney films (Chapter 7). This chapter shows how there is nothing innocuous about cartoons -- indeed, via accents and racial stereotyping, cultures are trivialized and characters that speak with “standard” varieties of English (or, “conformers” to the SLI) are praised by being consistently represented as “the good guy”. Thus, by watching Disney films, children are socialized into certain prejudices. The Disney example is useful because it provides a very clear illustration of how linguistic and
non-linguistic features such as race are often inseparable; Chapter 17’s discussion of linguistic profiling is another such example, although issues of race arise regularly throughout the book."
(you have to scroll down on the page to read the book review)http://linguistlist.org/pubs/reviews/get-review.cfm?SubID=4551704