I suspect that the 'gotta sing it just like in RUS..and in that order' syndrome comes partially from too many years in church...singing out of hymnals. I have a friend who does lots of choral singing, and he tells me with a grim face that most of those in his group would totally panic without their books in their hand, even though they have been singing the same songs for years...

A few of those singers may be converted to the 'if it's good enough to sing, it's good enough to learn' attitude, but not many.

Sad to say, we see the same tendency in certain TV sit-coms, where, from the theme music to the story lines and jokes, the formula never changes...some people just simply WANT it to always be the 'same' and never require them to think or adjust or incorporate something new....But that's why they HAVE different channels and a clicker...