Like all of us, Lou was entitled to her opinions. Hopefully she also realised, like most of us, that the 'folk scene' doesn't go in for commandments on tablets of stone. Who knows-perhaps she carefully chose her songs so that the problem never arose for her.
I can't help wondering whether part of this overblown problem is that people don't always pay attention to what's being sung. Looking back through some old set-lists I realised that I sing a couple of songs where the last verse starts like the first but, depending upon the structure, one or two lines are slightly different. A listener not paying full attention might well miss the, perhaps subtle, changes and assume I'd repeated verse 1.