AA,
I think the sheer scale of the US procurement system makes it easier to hide foul-ups. The F-111 is a classic example, years late, one variant cancelled, yet no-one seems to remember that UK cancelled their order, and bought F-4's instead.
The UK press love a good feeding frenzy on their latest football. It seems to be a national mental trait to only point out the bad stuff, and ignore the good.
Our American cousins are definitely possessed of a superior sense of optimism, Y'All!