[mhays]

Sea-Tac is expensive, but you misunderstand the reasons.

Here's the main one: It was necessary to build another runway so that two runways could operate in low-visibility periods. This required building a plateau high above the existing land, which was massively expensive. Worse, 20 years of politics and lawsuits were necessary to get it built, raising the cost substantially. The could would have been astronomical regardless of who built it. Not that it can really be compared...nobody other than a public agency would have the ability to build that sort of project from a financing or legal standpoint.

As for Southwest, they weren't supported for a bunch of reasons, starting with a lot of public expenditure that would have been required, such as roads and transit.