Without getting into a "what is folk" argument, I distinguish between the original folk tradition and the folk revival as reflected in folk clubs. I was referring to the use of guitar in the British musical tradition, where it was seldom found (although there are some examples). The guitar is widespread in folk clubs, but this is a feature of the folk revival. Without a true traditional style to emulate, a style of playing British folk music has developed which relies heavily on open tunings. That's not to say that standard tuning isn't also widely used.

With respect, Tonyteach1, your post did not ask about the advantages of DADGAD but commented that it seemed no more useful than other tunings. My point in reply was that all tunings have their strengths and weaknesses, and you have to pick the one that most suits the music you're trying to play.

The advantages of DADGAD is that it seems particularly suited to folk music, and perhaps expecially Irish music, for reasons which are set out above. In particular, the chord voicings seem to be particularly suited to tunes which are often modal (and let's not start another discussion about what "modal" means)

Personally I've never got on with DADGAD and prefer DADEAE (one of Carthy's tunings, although he's since developed it further)