I'm really enjoying this discussion, and I hope none of my comments are taken as arguments with what has been said. I value all the viewpoints you are offereing, more than I have probably said.

In the US we haev no-songsheet purists, too.... but I think the way people are using songsheets here at our place may be a little different from what many may have experienced-- I wouldn't like what you are describing, either. But when someone we know and trust, who has good musical taste, offers a songsheet, it's a way of saying they recognize that some of our folks are dot-readers, some are ear-learners, some want a copy they can take home and work on further, and so forth. It's a way of making the song portable, so that if one's memory is fuzzy later on they have not lost the tune or the words among all the rest of the stuff they played.... we sure don't pass them around as if one MUST use them. But we do encourage people who have a binder full of treasures to bring a few extra copies of a song or two, so that there are enough to share around. (Now, the person who owns the binder may or may not actually play from it-- at any given time, many of the songs they now know well enough to do from memory, so by now they don't really look at it themselves.) Often, this means that the extra songsheet will go to the best guitar player, so that they can show, via hand position, how the arrangmement goes.

Perhaps I also should add that we seem to attract people who have either just started playhing or who have always played at home alone, and have no idea how to jam or how to share things with others. As they are learning how to jam, the songsheet makes an entry point so they can join in easily on those saongs for which we have them. See? As they progress they get braver about not needing them. We don't force that; we honor however they learn or play and praise all the developments we see, including being increasingly able to play by ear and by watching hands... it isn't a crutch they hang onto for very long.

~Susan