I agree about sheet music. I feel that it is more often than not a hindrance to learning to play.

I think you're probably right about sheet music in relation to learning to play for folk music (which is what this thread is about) - but it's not easy to learn to play piano properly, or classical guitar for that matter, without knowing the dots.

Fort-five years after starting to play the guitar, then knowing very little music, I now find dots invaluable for all sorts of reasons. For traditional tunes, they provide a solid basis on which to build the variations you might hear at sessions (though I would never bring dots to a session) and, for more jazzy stuff, the intricacies of some chord progressions, bass lines, etc., they can be a godsend.

It's where to draw the line - that's the question...