Fellow Scouser:
Sorry, I missed your posting
"Where do they get these people?"
Where do they get them is right - one of the reasons I'm not happy with competition singing or playing.
I understand that some of the early revivalists broke with EFDSS in the early days of the revival because the Society organised a competition where they put young, 'in their prime' singers up against elderly source singers like George Maynard, and then pontificated publicly on the rights and wrongs of the singing.
In my opinion there is a great confusion on what we learn from our older singers.
Songs, certainly, but no young, or even middle-aged singer in their right mind wants to sound like an octogenarian East Anglian (especally if they come from Brum or The Pool).
This doesn't mean that there is nothing to learn about technique from them.
The two things I have noticed as being the difference between traditional singers and many revival singers relates to phrasing and tone.
The older singers tend to sing in speech patterns, breathing with the commas and full stops where possible and in this way maintaining the sense of the narrative. Clare singer Tom Lenihan went into some detail on this subject explaining how you had to "keep the sense of the story". He demonstrated how, when this wasn't always possible because of how the words lay with the tune, he would use short humming sounds "when there weren't enough words to fit the tune". - a fairly common device among Irish singers in general. He summed it up as "Sing the words as you would speak them".
Many revival singers, on the other hand, adopt what we used to call four square singing; breaking words up - best example I can think of is Liv-er-pool instead of Liverpool.
The other difference is that most traditional singers pitch their singing around where they pitch their speaking voice.
All this makes perfect sense to me when you consider the Irish "Say a song" rather than "Sing a song".
Just listen to Sam Larner singing 'Butter and Cheese and All'; he always interjected a bit of speech after the penultimate line:

"The dogs they barked, the children screamed, out ran the old women and all ("And you know what they are, don't you?" (spoken).

It is always a part rather than an interruption of the narrative - you can't see the join.
Jim Carroll
PS Sorry CS - not sure if all this is relevant to your question - a hobby horse of mine.