I have never been able to figure that out. Why do the very people who look like heroes flying the A-10 hate it so much? The public loves it. Our enemies fear it. It works like a magic death cloud. It's durable as all hell. And it's relatively cheap. What's not to like?
Truly, part of the reason is that is is cheap and was designed a long time ago, and does not need to be replaced.
DoD, in large part, exists to spend money and provide jobs. They need to support a defense instrastructure (Lockheed, Boeing, Northrop Grumman, etc.) For this to happen, money must flow. Lots of money.
What this means is that there is a strong incentive to always buy NEW things which are EXPENSIVE and which MAY NOT WORK. If you do this, money will flow and flow and flow.
A rock solid, cheap aircraft that was designed 40 years ago and doesn’t need to be replaced??? Who the heck wants that??
What *I* think:
The air force likes its sexy fast movers. It accepts bomb trucks. It HATES actually getting down and dirty.
Ground support is for some reason considered by some in the hierarchy to be far less glamorous.
The F35 can do some of the glamorous high speed at altitude stuff.
“Cheap” is the operative word. Things that work AND are cheap tend to get short shrift in defense spending circles.
The USAF does not want to do Close-Air-Support. Never have. They want to fly fast, and usually high. They will fly low if they are doing it very fast.
But the USAF is so parochial they will NOT give the US Army the A-10 and let them operate it. With the exception of one or two highly specialized aircraft for the Army, the USAF owns and pilots everything with fixed wings.