Excellent analysis and summary, Codger!

Mike, people who like to sing together from books may not find churches to be their favorite venues, not only because they may not be religious (or they're folkies of diverse religions), but because it's hard to get up and get your voice going on Sunday morning after a long night at the folk pub.

Crow Sister, and others, I find the juxtaposition of these two arguments in this thread interesting, if not amusing:
1. Books are bad because they end up lowering the quality of folk music performed in public and contributing to folk music's not being taken seriously.
2. Using a "special book for everyone to safely all sing the exact same songs together from in the exact same way" is less desirable than having the lead singer do it all from memory and others joining in as they can, even if it means sometimes not everyone is singing the same version.

Seems to me that if other pub customers or audiences are listening and quality is important it's better for all the singers to be "on the same page of music" -- both figuratively and literally -- because it makes for a better performance.   
Strictly solo performances are one thing, but where group singing is involved, if excellence is the goal, either stick to very, very familiar songs (that "everyone knows by heart") or maybe it's not such a bad idea to use a lyric sheet.

(Rise Up Singing, as has been said before, does not make a good "hymnal" for sight-reading because of its type size and format. It is not user-friendly as a lyric/chord sheet except for research purposes.)