"Oh, you'll have to audition if you want a slot at our club,"
Sorry to take up a point made some toime ago - attending a local singing week-end where the standard is excellent, including a number of superb young singers barely out of their teens.
I don't see any suggestion whaatever of 'auditions' here; this seems to me to be a much-dragged-out red herring to excuse allowing singers to practice in public, which is highly unfair on both audiences and singers who have done the basic work.
It isn't rocket science for any half-awake compare to spot somebody who can't sing in tune or is reading a text from a printed sheet (no - not having words available just in case - we've all done that).
If you are allowing members of the public in there needs to be a standard below which you do not fall, otherwise you are selling the music and the public short.
If a club is serious about assisting new singers, set up a workshop for beginnners, or at least create a situation where the more experienced singers can make themselves available to offer help.
Unless there is something physically wrong, anybody with the desire to do so can sing - the harder you work, the better you become.
The pleasure of singing in public lies in making the song work, for you and for the listener.
Jim Carroll