Folkie Dave.
Why not name these three bands and let's judge for ourselves from their gig lists.QUOTE.you are confusing popularity with quality.
    The best band I saw this year as Top of the Bill was Kathryn Tickell. Pure tunes without singing for 1 hour 30 minutes. Hardly rock and roll.QUOTE
Yes, but nothing to do with folksinging.
your personal top of the bill,just tells us about your taste ,nothing else.
Generally speaking,at least 80 per cent[there are a few exceptions],folk festivals have become a Pot Pourri,a musical jamboree.
The purpose seems to be to put bums on seats,and pander to the next commercial pop/folk trend,these unfortunates a few years later are discarded,when the next so called exciting act comes along.
Groups/ singers,become throw away commodoties,who can be replaced,by the next hyped[wondersinger /band],all that appears to matter is finding a new wonderact each year.
moreover most festivals[in the UK] take place,in complete isolation and do not involve the local community at all.