Right, I suspect this is voicing a much older consensus about effective storytelling and good art:

If you want to send a message, use Western Union. — Frank Capra (director of message-heavy films like Mr. Smith Goes to Washington and It's a Wonderful Life)

Given his filmography, it’s pretty clear Capra didn’t mean that politics should be avoided when telling a story, just that the story should come first. The idea is that any “message” a writer might convey will naturally be embedded in the stories they tell, whereas writers who attempt to construct a story around a particular message tend to fail at delivering either.