It isn't the gates at SNA. It's being right next to (and socked in by) upscale neighborhoods. It makes for bizarre takeoff patterns where you'd swear that the engines must have failed one minute after takeoff, but it's just noise abatement. There's drastic limits on expansion. The gates are underitlized some parts of the day, but the airlnes still can't add flights.

The official solution is supposed to be to build a brand new (and much bigger) OC airport somewhere else. But every time a proposal comes on a ballot, NIMBYs vote it down.