"He enjoyed narrative as a sensation; he did not wish to swallow a story like a pill that it should do him good afterwards. He desired to taste it like a glass of port, that it might do him good at the time."
Okay, that was technically two sentences, but once I got started I couldn't stop. It strikes me that Chesterton has- as he so often does- put his finger on a problem which infects many modern works of fiction, both written and on film. That is, sacrificing a good story on the altar of teaching the "great unwashed" a lesson. How often, for example, have you watched something over the last number of years where it's seemed as though the entire plot- what there is of it- is formulated around the desire to promote some sort of message: 'climate change is a calamity' or 'men bad/useless, women wonderful, smart, and strong'... to pick a couple of examples at random. It doesn't seem to matter to the writers/ filmmakers if the plot is good, enjoyable, or even coherent; all that matters is the message. The purpose is to lecture and "educate" not entertain and inspire. Take it because it's good for you, not because you'll enjoy it.
Now, I'm not saying that there can be no good works of fiction which contain a message- far from it: there are many that do. But well done ones tell a rip-roaring good story and trust their readers/viewers to parse out the underlying themes, not repeatedly hit them over the head with the message until they forget what the plot was about, if they ever knew. Port is a sweet wine which is often served with dessert; modern writers would do well to remember that, in the words of Mary Poppins (from a time long gone when Disney could still produce good movies) "a spoonful of sugar helps the medicine go down".