I agree with you that debt is at the heart of the problem. This doesn't change the fact that it was the the debt limit fiasco which resulted in this specific decision to downgrade the US credit rating. Maybe, it is possible that the people who caused this to happen were trying to solve the problem. The winners of this fiasco declared the process that took place a historic victory and a template for future political aggression. If Sarah Palin was the head of S&P, then this fiasco and how it played out would have been a positive factor rather than a negative. As it stands, this fiasco, in the eyes of the S&P was not a positive thing, and is in fact, as they claim, what made the difference between being downgraded and not being downgraded.
Of course S&P are not perfect. They have their views and others have other views.
While I observed the fiasco, and observed the positions and tactics being used, I had the opinion all along that this will result in a negative economic impact for the US. The economy is based on confidence. They may have wanted budget cuts, but they went about it by threatening the country with default. It is not rocket science to realize that such as threat and a last minute decision on wether this would happen, will be a confidence killer. I remember hearing Wolf Blitzer saying something like, he thinks we will avert default, but that at this point you can't be sure. And one side of the debate made it clear that they were willing to default if they didn't get their way.
And, it was obvious all along by the positions that were being taken, that it would be a last minute ditch to prevent default, or that there would be a default. They stood on there principals so firm, knowing in full how it would play out politically. They were either too stubborn careless or stupid to realize the economic impact it would cause. If they are competent then my verdict is that they were protecting their special interests even when it would hurt their country. And then they call it a historic victory for great american patriots. More like great american idiots.