Harpers play more eighth notes than anybody else - the instrument is so quiet that you need all the twangs you can pack in. Divide a long note into a four-note arpeggio and you quadruple the sound energy.

Which said, I basically agree. Look at the version of the Mason's Apron in my session tunes file - it's the way I play it, and I think the tune comes through much more clearly than in any of the printed versions with their obsessional arpeggiation.

Catriona Macdonald teaches by getting people to sing the tune before picking their instrument up. That's a good way to discourage gratuitous note-spinning.

Actually, people ought to learn to split and combine sub-beats on the fly, it's a useful way of generating variety. With an instrument like the recorder you can usually leave the fiddlers standing and fracture a reel into semiquavers if you want to.