At the end of the day, too, it’s an age-old argument from a promoter’s POV: Do you book a band who will draw like crazy, and who (to an extent) match the fest’s intentions as a means of ensuring you get turnout? Or do you stay “traditional” and hope nothing goes downhill?
In my opinion, no one who knows what they’re doing would book SCI without knowing they’d both draw a ton of people AND jeopardize anything that pre-existed. I don’t really like SCI, personally, and I get disappointed every time they’re announced as a major act at a festival I will be attending (because I think immediately of 15 other bands I’d rather see), but them’s the breaks when it comes to festivating: I’ve never liked every act at any fest I’ve been to, but I think I can figure out why those acts were booked, even so. At Telluride, honestly I’m happy to have a headliner, or a nightgrass slot, or whatever, that I’m not into, since it’s so rare. And THAT’s what I love about Telluride.
Too, a new promoter might mean a festival taking a different direction. You should voice your opinion loudly about that, to that promoter, if that’s a struggle/problem, but the simple fact is that you might not agree with the direction it’s going, and that might be beyond your control. Speak with commerce, y’know? Either go or don’t.
Either way … FOM makes a good point; it sounds like SCI catered to the event to the extent that they were able to without disappointing the fans who potentially came just for them, which is kind of remarkable. I don’t think you’d see a lot of bands do that. It reminds me of Counting Crows’ almost entirely acoustic set in '07, and I’d venture to guess a lot of the “traditionalists” didn’t really care about Counting Crows and were already jamming at their tents or in line for Nightgrass at that time anyway. It’s about the spirit of an event, and honestly a lot of events don’t have much spirit to speak of, to begin with.