"...Bright Star has very well composed music in the context of the genre."
I'm a musician and gladly confess I have no idea what such a statement even means, particularly seeing that both composers of the piece are known to not be able to read or write music (a la Mel Brooks), but rely upon an arranger to create the entire harmonic language/structure of their work.
I've been listening to bluegrass since childhood; my favorite theatre-bluegrass score is The Robber Bridegroom (the original, not so much the recent revised version). To me, Bright Star's score, although often very pretty, lacks wit, humor and character/situation specificity, things that The Robber Bridegroom achieves quite well.