Ego's a big part of it here. The Air Force has historically demonstrated disinterest in programs that aren't "sexy," which is high-end fighter aviation in a nutshell. It's not just fixed-wing close air support that's hurting. It also manifests in the USAF not buying enough tanker, airlift and other assets to do the job.
It's more a matter of the A10 being the craziest aircraft attached to a gun, ever. The aircraft was basically designed as an answer to the question, "how do we put this cannon where we need it in a hurry?"
An argument could be made, when considering the Air Force's costly desire for sexiness, that we will also be paying for the 2003 campaign of Shock and Awe for many years to come.
