"Why is it so important to distinguish the workaday "broadside hacks" from other working people as creators of song texts?"
For the same reason you attempt to distinguish the work of craftsmen from that turned out on the conveyor belt - one is produced for profit, the other because the maker brings something else to his or her creation
It is the case with all art
The iporance of who produced the songs lies in the possible reason they were made in the first place - the Steves go for money and simple entertainment, I have come to the conclusion that it is far deeper than that
The lives of people are reproduced in microcosm in whole genres of our folk repertoire

Take the social misalliance songs or those of arranged or forced marriage
At the time many of them were made, society was shifting, the old order of gentry was being replaced by the successful tradesmen who sought land and power
A presentable daughter was not just a 'joy to behold', but she was 'money in the bank' for an ambitious family - a step up the social ladder.
The human effects were reproduced in many songs.
One of the most remark examples of this is the ballad 'Tiftie's Annie'(Child 233)
On the surface, it is a family tragedy, a young woman associates with a servant to a local lord, the family disapprove the liaison and o to extremes to prevent it, and eventually beat her to death to prevent it
A powerful plot, worthy of the greatest writers anyway
Start digging into the ballad and it becomes even greater
THere are whole layers in the ballad - at first it's fine to fancy the servant, even the mother does, but, once it goes beyond that things get sertious
First they take the piss on the match, then they lock her away and when they realise the girl is serious, the father writes to Lord Fivie accusing him of witchcraft:

And Tiftie's penned a long letter ands sent it off to Fivie
To say his daughter was bewitched by the servant, Andrew Lammie

Andrew is forced to answer the charges in Edinburgh and while he is away the girl is systematically beaten by all the members of the family in turn until her back is broken - they would rather see her dead than risk the rise of the family fortune with a disgraceful match
The added importance of the ballad is that it is based on traceable historical characters
We visited Five Church - there is a large stone tablet on the wall in a very prominent position honouring local miller, William Tifitie.
WE couldn't find the daughter's grave, but some time later local folk enthusiasts located it and cleaned it up.
The mill is marked on local maps
Making a ballad on this incident would require local knowledge not available to a town songmaker and the subtle skill that went in to its making is way beyond that of a townie hack

THe folk repertoire throughout Britain and Ireland abounds with such creations, mostly on a smaller scale, because the situation that prevailed was common to all
When Harry Cox sang 'Betsy the Serving Maid' to Lomax and spat out; "and that's what they think of us", he made it quite clear that he was aware of the social significance of the song - it puzzles me why people here can't grasp that significance.

"but of changing tastes."
I believe the greatest mistake made in trying to understand folk songs is to take them out of context and treat them out of context
Great art is multi-layered - ranging from simple titillation to historical and social information -
Dickens is probably one of the finest examples of this, from the death of Little Nell through the upheaval caused by the Industrial changes taking place, Revolutionary Europe, squabbles over inheritance of property, the mechanics of the Law, the Gordon Riots... to surviving on the London streets
All a magnificent artistic dip into 19th century Britain presented in magnificent prose
His mate, Wilkie Collins, with his obsession of a woman's right to inherit property, produced highly enjoyable early feminist novels - and one of England's early detectives.

I believe our folk songs did the same on a smaller scale, but in a way, a far more important one
They are small histories of a people who has been largely ignored by historians, made by the people who experienced the events the songs deal with.
THese are all only possibilities of course - even the two Steves have admitted that, but if it is a possibility, it's surely worth consideration
Little sign of that so far - people can't even bring themselves around to considering the possibility that workig people produced songs about their lives, and have gone for the commercial theory with the enthusiasm that a terrier goes for a rat
Beyond me, I'm afraid
Jim Carroll