Actually Jim, I think there is a lot of evidence that songs the origins and author of which are known also, over time, undergo change and variations - it is not unusual to observe that on song threads here on Mudcat. (The recently revived Belfast/Aragon Mill thread is one example.)

Music scholars and researchers, such as yourself, musicians who perform and who are scrupulous to credit where they got a song, and those who use sheet music to learn a song, or need to research whether or not a song is copyrighted to know if royalties have to be paid - are all people who will know or discover whether a song is "traditional" in the sense that no one knows, anymore, who wrote it.   Most people who sing or play or otherwise enjoy music and song are none of the above.

Mayhap the reason traditional songs do not have a name attached is because the singer/songwriter lived in a place and time where stuff didn't get written down, or if it did, it didn't get archived, much less copyrighted. It may well be that many of them cared that their names were attached, but the technologies of the time did not make that possible, at least not beyond their small community, and perhaps 1 1/2 generations. The basis of the oral tradition, at the loss of specific origin that goes with it, was simply that was the best way, given the readily available technologies of the time, to try to preserve and pass on any knowledge. It seems to me that our human tendency has always been to capture and preserve as much knowledge and information as the technologies available to us permit.

Having written all of that, it occurs to me that I might not understand what you intend by "traddie." Maybe there is a modern tradition in the UK of people who write songs and ballads in the style of traditional songs originating in the UK and/or Ireland, with the intent that they be disseminated orally and without attribution so as to enter "the tradition." In other words, they hope to avoid the song being identified as originating from them.