I don't think any of us are promoting blanket criticism. There are bound to be a few exceptions. It's a matter of common sense and a degree of tolerance. We are really discussing amateur performance here and my experience of the folk scene is that professional performers would not use crutches in this way anyway. If I may 'we are all reading from the same hymnsheet' Ooh, that was bad!

The only problem I would see from your good performer using a crib sheet/paper copy etc. is that other lesser mortals see that and think it's okay, and before long you have a club full of readers with their noses in folders.