Mary, I don't think we're in disagreement. It really can be very disruptive when people hold up the song while people look it up in the book.   (If I do a song that's in RUS and it's a group where people have the books, I may tell them "It's in the book" or even give them the page, if I know it, but then go ahead and start the song without waiting till everyone finds it.   I've also been known to say "This song's in the book but I may not use the chords they have."

One thing I really do not like to do is follow someone else's idea of the "right" chords if it's a song I've worked to commit to "muscle memory," because playing those alternative chords will interfere with that.    And in some groups you're expected to use the lyrics and chords in their designated book even when you choose to lead a song you've been doing a bit differently for years.   I can't say I totally stay away from groups like that, but I'm not all that eager to participate in them regularly because of that kind of conformity pressure.

It's like your Sloop John B experience, Don.
I've developed my own arrangement of many songs, sometimes (frankly) because I couldn't copy the guitar work on the recording I first heard and sometimes just because I prefer different chords, different rhythm, different style.    But many of my top-notch guitarist friends have the original (or best-known) artists' licks down pat and react as thought I'm "wrong" when I play the song a little differently, even if I haven't changed the melody or lyrics and when my chords work just fine with the tune and harmonies.   It's as though a song were carved in stone.