New Earth as a parody and critique of capitalism and British culture.
New Earth has a lot of themes that can be interpreted as criticism towards unjustified experimentation and capitalist exploitation. There's experiment subjects and even people who are manipulated as mere objects. There's the weak that get exploited so that the few can remain healthy, Cassandra's xenophobic views were left ambiguous in the past but over here she gets portrayed as something akin to a capitalist, white supremacist, and there's people like her that are too selfish or apathetic like to try to change things until the Doctor shows everyone a better way.
