"No rule says that written English has to use the same word order as spoken English, or that writers can’t play around. But a writer who introduces awkwardness should have a reason."

Says David Owen, in "The Objectively Objectionable Grammatical Pet Peeve/A semi-attentive investigation into a confounding sentence type" (The New Yorker).

He actually is stating a rule. It's just a very general rule and it has a very general exception. He just can't force writers to follow that rule, and he's written a long article railing against one very particular type of variation from natural spoken-English word order: