an insightful critical mind is necessary to become a good musician.
it is necessary to listen to oneself and criticise,it is necessary to listen to others,have an insight into what they are doing, and learn.
to be a good musician requires discipline,insight,and a critical mind.
Smedley,are you a musician,if you are I am surprised you ask the question.
Practising, requires analysis,it requires criticism,and it requires insight,to become a good musican practice is essential.so musicians are [imo]well qualified to be music critics.
if we accept that everything in the garden is rosy as regards musical criticism,and that amatueruism is acceptable,logically it becomes acceptable that amateurism is acceptable in the performance of song,if that is the case ,god help the folk revival and folk song.