As another Celtic musician (harp), I learned my instrument by ear rather than through sheet music; while due to classical violin training, I know how to read sheet music, to me printed music is largely lifeless, and can even be a barrier to understanding the music itself. When you have to break down a song and learn it by ear (and memorize it quickly!), you acquire a sense of how the music works that sits deeper than that gained from sheet music, where you continually have a reminder of what to do next, avoiding the need for such internalization. With a background like that, I can’t get the sense of a song very well from sheet music, and so it is not enjoyable to look to paper as a substitute for the sound. On the other hand, that’s just the musical tradition I’ve been trained in; the classical tradition has grown out of a broader European urge to write things down that began a very long time ago (9th century, I’m thinking, but it’s been a while since I’ve checked), and so someone trained in that style may have a more ‘positive’ relationship with printed music. I would think background rather than ‘level’ has a lot to do with it.