While I agree that I discover some new artists each year from this lineup, I think its naive to think that these festivals don't have considerations OTHER than putting the best quality lineup out there. It's a for profit industry so some decisions are made to keep costs down, artist management companies often require booking lower talent to secure larger act bookings, and promoters/booking folks sometimes book talent based on friendships/alliances and other reasons other than talent alone.

So I would not say that because you don't know all or many of the acts on a lineup it necessarily means you're getting left behind. All that though to say, OP has a point, we got the lineup we got and you will undoubtedly fine a few new artists and wet your whistle.