Whatever the club rules etc are or are not, I for one would get totaly pissed off if someone was so rude as to talk, walk around & generally ignore whoever was singing.
I would sssh them & tell them if they want to chat go to a pub & not a folk club.
If it was people singing in the pub then fair enough ingnore them & chat if you like but if someone has paid to see, listen & join in the singing then they have that right. Just as whoever is singing has the right to be heard.
Cheers
Les