I think the bluegrass audience has many more participants (pickers) than the folk audience. In fact, the bluegrass culture includes going to festivals and pickin' your brains out all weekend, skipping meals and sleep to jam all day and all night. People who never picked up an instrument before end up taking up guitar or mando or banjo or fiddle or bass and joining in. That's part of the attraction of bluegrass, the welcome to beginners and the campsite jams ("field picking") in addition to the stage shows.

At the folk festivals I've been to, there are a few people who play some instrument or other (many more to pick from in folk music), but not nearly the widespread participation that is standard in bluegrass. And folkies rarely jam until the stage show is over for the day, while some bluegrassers never even get down to the stage area.

My personal opinion about those folks who go crazy for pickin' speed and dazzle is that it's another gearhead thing. The same ones (usually guys) who are into cars and machines and things with PARTS are the ones who spend hours, whole weekends, talking about (usually) banjo PARTS and licks and breaks and such. Don't get me started on banjos. I live with one. Make that, I live with FOUR.