It's more honest than Autocues. A good performer will use such aids without having his/her performance affected in any way - unless dance routines are incorporated into the performance of course. But we are not talking Westlife or Beyonce here - the nub in a folk song is the lyrics, not the prancing.

I know that a lot of people put great store on a performer's not using a "safety net" of any description. To me that is of no importance per se. I have seen people waste so much concentration on remembering lyrics that their interpretation of the song is affected. And I have seen people stop half way through a song, put on glasses and leaf through a book to find the right page before continuing. Both are bad IMHO. The argument should not be whether a safety net is used, but how well it is used (ideally unobtrusively).

The above certainly holds for live performances. When it comes to singarounds however, I find the subject totally irrelevant at best (and just an opportunity for "holier-than-thou" criticism at worst). Singarounds are not "performances", they are opportunities for ordinary people to have a go. Any criticism that attempts to limit that opportunity (he/she uses safety net / has crap voice / can't hold a tune in a bucket etc) is detrimental to the benefit of the singaround.