Fox’s formulaic TV competition, “So You Think You Can Dance” isn’t really about serious dance, any more than American Idol is about serious singing. But this season, a real dancer (Danny Tidwell from American Ballet Theater) has joined the ranks of So You Think’s contestants. The result? At least one judge hates him, he’s perceived as arrogant because he actually knows what he’s doing and won’t mug for the camera, and he was nearly voted off by the audience last week.