There's something in what the Captain says but descriptions like 'boring' are pure subjectivity. Virtuosity is a much over-rated facet of music generally and right hand technique was what gave bluegrass its unique selling point, in modern jargon. Even so there's a lot of bluegrass that doesn't rely on speed for impact. Clawhammer and two finger playing lend themselves less to bravura technique but are still bluegrass. I like old timey too but feel no need to make a league table out of it.