"songs about murdering your baby"

I wonder how many people who sang those kinds of songs back in Ye Olden Folke Times, actually killed their own babies? Not many I presume, such an admission of infanticide would probably got you as far as the 3rd verse before the audience turned on you and some form of constabularly was trying to get to you (to hang you officially) before the mob did (unofficially).

Similarly, do people have to commit crimes in order to have 'permission' to sing about criminals. I've been in prison myself, but would have had to have specifically been in Folsom before I sang 'Folsom Prison Blues'?

There's a lot of social commentary in folk music which is still relevant today. Whilst the specifics might be different (in Britain, there's very few 'folk jobs' left following the downscaling of employment in heavy and light industry), the principles are the same: people at the bottom of the pile getting shafted by the people at the top of the pile.

Also, since a lot of those jobs are no longer in existence, a peek into a world that no longer exists in the same way is pretty important. Lots of miners and agricultural labourers in my family tree and songs involving that kind of work are of interest to me: those folk stories are my relatives stories and I'd rather stories like that weren't forgotten.