Also, "we are all politically active" doesn't mean that they agree on every current, urgent issue. Sometimes "let's talk about something else" means the person doesn't want a nine-against-one argument. Sometimes she's carefully not asking her friends what they think about a specific issue, and really doesn't want to deal with that as dinner-party conversation.

And sometimes she has a far bigger dog in this show than you can even imagine: your dystopian thought experiment is her wearily lived everyday reality, and she’s fed up with well-intentioned Politically Enlightened! people reducing her to her suffering.