I can't imagine why it hasn't been theatrically released yet. It's got a great ensemble cast, with Sutherland, Lane, and especially Chris Evans doing spectacular work. Wake up, studio execs!
The story is based upon the experiences of the author/screenwriter, growing up as the "poor kid" in an extremely affluent community, where class is everything, and makes a difference in every aspect of life, from clothing to justice.
During the film's Q&A, the author was asked about his experiences, and particularly what we don't know about the ultra-rich. He said they aren't stupid, they're very smart (as opposed to how they may portray themselves), they've got plans, and they are a threat!
In many ways, this film is extremely timely.