Well, it's right. By cramming in passengers and giving them an incentive not to bring their baggages, as well as having a young fleet of fuel-efficient places Spirit is plenty green -- both in dollars and in eco terms.
Spirit responded to the DOT's 2011 ruling regarding fare disclosure by claiming in advertising that the higher prices were government charges as opposed to fees like tacking on for boarding passes or booking with a credit card.
Using first amendment argument to display real costs to consumers? Now that's novel. For once, a consumer victory against airlines. Surprised to see Southwest, one of the most consumer friendly airlines, involved in challenging this ruling.