I recently critiqued a spate of unpublished manuscripts that were well written for the most part except for what I refer to as "literary retro," and I thought it might be a good idea to address what my phrase encompasses.
For many readers and writers, the most obvious instance of "dated" writing is material with excess comma usage that mirrors the respective styles of Henry James, Jane Austin, and other Victorian-era authors of classical literature. But the problematic issues with antiquated writing are much more extensive than abundant commas, and include placing a character's thoughts in quotations, combining different tenses, and awkward POV shifts. And many of the worst offenders are recipients of literature's most prestigious awards.
Kafka wrote the metamorphosis approximately 100 years ago. The work's value as a dream-narrative is indisputable, but the author's quoting of thoughts can be misconstrued as an acceptable technique--when it is not. Bob thought, "What can I do now?" is going to rapidly send a manuscript to the slush pile; whereas, Bob wondered what he was going to do next, while not scintillating writing (and flagrant Telling and not Showing), would not in itself most likely discourage an agent or publisher from continuing to read the draft.