It looks as though DIA is going to help Frontier expand, while keeping the gate open for United, if it ever gets its act together. I'm happy to see Frontier expand, but I'd prefer that they get some of United's gates. If United ever gets back on its feet, then we can shell out the money to expand. There's no doubt that part of Frontier's expansion is coming at United's expense, and I'm worried that we're liable to end up with a great deal of excess gate capacity, and excess maintenance cost.

As to the question of why this matters to people who don't live in Denver, consider your own airport. If it's in a major market, chances are it's in the same position: a hub for a major carrier, with other major, minor, and regional carriers scattered around the outlying gates. All the major carriers are in trouble, and almost all the major airports seem to be stuck with these long-term, inflexible plans. The net effect here is to subsidize a failing whale, while stifling the nimbler, more agile, smaller competition that makes a market system work. Replicated all over the country, such arrangements could end up making air travel even more expensive and inconvenient than it is now.