Jon,
Remember these are sophisticated literati we are talking about. What we see in a ballad as charming, the fast-moving plot with lots of action and pathos, they would see as something ridiculous, to laugh at, burlesque in other words.

In a similar way, but not quite the same, (still burlesque) the fledgling Music Hall artistes of the early 20th century took our ballads and put them on stage as something to make fun of. The burlesque was often in the performance without altering a word, in the form of ridiculous costume and gesture, funny voices etc. They were so popular that they were also often parodied.

Lord Lovell
George Collins
Cruel Ship's carpenter
William Taylor
Barbara Allen etc. all received the treatment.