"And if they then wanted to publish it and get paid, why not, "
No reason at all
It has never been a question of them appearing on broadsides - that has always been accepted
It is a question whether the orinateded there
Much of the argument suggests that they did and the reasons given for that (when they have been given) I find unconvincing
If it is true than i means our scolars have been barking up the wrong tree from day one and people like me who have been approaching our folk songs as social history have wasted our lives.
It also meand, of course, that working people have always been recipients of (even customers for) our oral and musical cultures and not participants in their making.
Doew 'Duncan Campbell' sound as if it was made for money - of course it doesn't
Do the Beethoven Quartets sound as if they have ?
Money or sponsorship certainly played a part in the circulation of both but that is no indication of the motive behind their creation.

What do sound as if they were created for money are the many thousands of badly written and largely unsingable broadsides which, it is claimed, share their authorship with our ballads and folk songs
"It's a much more interesting book "
"Interesting" doesn't really come into the equation - I love John Griham anc C J Sansom, but I go to them for something else
Jim