I partly agree with Jim Carroll,I do not find Nic Jones a good interpretative singer, however he does have a good voice which is pleasant to listen to but Canadeeio and many of his guitar arrangement are spell binding and worth listening to as instrumental music much as a music afficianado might listen to classical music or jazz, he was a phenomenal insturmentalist.
next point,imo there are some traditonal singers who also are not good singers, either there voice was knackered or thsy had no idea about interpretation and sang in a dead pan way.
Ewan MacColl imo was not any better singer than Nic Jones, but for different reasons his approach was theatrical not natural he lacked any spontaneity.
a matter of taste, but neither MacColl or Jones would be singers that inspire me, however I could listen to Jones purely for his instrumentasl ability and to MacColl for the high quality of his songwriting