There may be all this race and ethnicity switching in the movie, but same treatment does not mean it is equal. Sameness is not fairness. Halle Berry and Bae Doona wearing making up to look white? That action has no historical oppression behind it; it has not barred white people from enjoying great roles. Tom Hanks and Hugo Weaving portraying women? It’s been done since Shakespeare’s time (probably before his time) but not to the extent that women aren’t prevented from playing rich, complex roles today (although honestly the roles which women could play can still improve).
However, white actors being made up to look Asian? THAT has history steeped in systematic racism which still effect Asian American actors today (often a sad choice between playing stereotypical roles or simply being a background/invisible). Cloud Atlas is only perpetuating that systematic racism. The fact that they resorted to yellowface is not negated just because it is pillowed by other switching acts because these acts don’t carry the same history of oppression as yellowface does. That history can’t and doesn’t magically disappear within the context of the film. And the film can’t be treated like it’s in a vacuum of space and time - it’s situated in the bigger picture of today’s society where we can’t deny that there is a painful lack of Asian Americans in the media.
So why - why is the context of the movie privileged over the context of our society where Asian Americans are continued to be discriminated against?