stop being obtuse,you   know very well,that many clubs in the past[and some still are] run/financed by one person.

No problem with that at all but if anyone chooses not to go to a workshop that is up to them.
Thats bloody obvious too,and that is part of the problem.[Isaid earlier you can take a horse to water but you cant make it drink]
the singer on one of these threads who had listened to herself,and realised she was going quarter tone sharp,by the end of the song, had the right idea,critical analysis of her performance.
not that I think it matters too much if an unaccompanied singer does this,more important is singing in tune and interpretation.