Addressing several messages:
Broadside Ballads etc.: yes, of course every folk song was written by someone in the first place. One common attribute of folk songs (hell, you can't define* it) is that they have stood the test of time, so that the song lives beyond the memory of who wrote it. By that criterion, some of the Lennon/McCartney standards have achieved that status. In contrast, my flesh creeps when somebody stands up and introduces a trad ballad with 'This is a Kate Rusby song' (unless it's one of the few she did actually write from scratch). I mean, by all means credit who you learnt the song from, but allow for the possibility that other versions exist, and why not do the research and find a different version or put one together that's your own.

The failed pub-rock singer syndrome: I agree that the "anything goes" attitude of most clubs doesn't encourage high standards. I really don't know what to say or do about that. Folk music is by and large an amateur activity (or is it? it doesn't seem so much so in some countries) and everybody has to start somewhere.

US/UK differences: What is often called 'folk' in the UK is called 'Celtic' in America (even if it's English, and that's another can of worms) when 'folk' means a particular type of singer-songwriter-guitarist style where everybody want to be Woody Guthrie or Bob Dylan or something.

*Definitions: I don't have a problem with not being able to define folk. We all know the difference between night and day, but we don't have to argue about the precise point in time where one becomes the other.

Anahata