I'd like to pick up two of Jim's points.

"You only have to look at the collections I mentioned to see that there appeared to be very little artistic creation in their making, none of the subtleties that you find in folk song and certainly none of the humanity
In folk song ou get sentiment and compassion, in the broadsides you get (often very exaggerated) snitmentality"

That is again making a black and white distinction between broadside ballads on the one hand and folk songs on the other, ignoring the overlap. Do you have some particular songs in mind as examples of subtlety, sentiment and compassion?

On the Maid of Australia thread you said
"it was Professor "Bob" Thomson, who was the first to put forward the extent to which folk songs appeared on broadsides (circa 1970) and who based his PhD on the subject"

Many scholars and collectors before and since have commented on the words of collected songs being found on broadsides. Was Prof. Thomson referring to the particular case of songs that appear to have started with the "folk" and then got printed?