"Where does the notion come that a song in which bad stuff happens should be shunned on the grounds that it is recommending that listeners act that way?"

A fair point (although for myself I've been speaking purely personally and not demanding that anyone else shun anything). One of the distinguishing features of the great traditional ballads is that, in general, they don't moralize on the often violent or distressing events they describe. The ballad narrator is more often than not a neutral observer.

'The Wife Wrapt in Wether's Skin' is a very different story, though. It's not neutral, but sympathises 100% with the husband, presenting the beating of his wife as entirely justified by her laziness. To quote one version, he "makes the ill wife good" while, in the the version Al mentioned, other similarly afflicted husbands are urged to call up 'The Wee Cooper of Fife' to teach their own lazy wives a lesson. I don't think that it's possible to sing that song without seeming to sympathise with domestic abuse - not without a rewrite, anyway.

In 'Peggy and the Soldier' the story is told from a less subjective standpoint, but it still portrays the protagonists in a very black-and-white way and, to me at least, suggests the implication: "that's just typical of a woman". The Good Soldier said above that the story is "typical of life", but I'd hazard a guess that many more men walk out on their families than do women, so although the scenario of the song no doubt exists, it holds up a distorting mirror.

All I'm suggesting is that we think about the stories of the songs we sing, about whether we're sufficiently comfortable with them to give a committed performance. Different singers will draw the line defining what's acceptable in different places. Personally, I don't think that the fact that a song sounded great when Paul Brady or Martin Carthy recorded it is sufficient reason to want to sing it myself.