Well, don't ask me for sources or anything like that, but I really think that DIA was a good decision...okay not at the time it was made, but today. First, people usually think about big projects in terms of the present or near future. However, if traffic continues to increase in the next 10-15 years, as the FAA is forecasting, the US will need more hubs, more runways, more gates, more of everything. While I don't think DIA has been what Pena and the mayor hoped it would be, the airport can, and I think will be VERY successful in the future. Colorado and Denver are well poised to accomodate any growth in air travel. They are currently at capacity, but they could grow all the way to Kansas if they needed to (lol)
No matter where you look, virtually every major airport is at or near the maximum capacity it will ever be able to take...except DIA. Well maybe the others will be able to expand, or build a new airport. Well, look how long it took Denver to get the plans done, the taxes approved ,the airport built, then opened, then successful. We're talking about twenty or so years. In twenty years, the airports that are at or near max cap now will be scrambling. And how much will a new airport cost then (w/ inflation and everything?) maybe well over $10 billion, who knows.
Oh well, only time will tell
P.S. I know some of you are going to ask for sources, but everything I wrote is just a compilation of things I have read, heard, or thought of. I don't care to defend the credibility of any of it...