That makes no sense at all.
Does it need to?
Maybe, maybe not. People don't really have to make much sense; but generally it's the people who act with some kind of planning and control and rationality that rise over those who don't, which is a source of continual hostility for the people who are passionate and who do care. The USGov is hardly a pack of staunch nationalists with mob mentality, there's a lot of careful manipulation and planning that goes on (not even including mass conspiracy theories).
The private sector has as much, if not more, to lose by the US economy taking a dive than the ordinary citizens. Hell, of all the classes I've been to, the only one where the professor seemed most concerned about international affairs as they pertain to the national economy was one on business.
If the dollar tanks, so does the value of every single business that's tied to the dollar.
Of course it does have a lot to lose. But the way I see it, the private sector entities are what have caused the current economical criseling, and the government has allowed it to do so.
The ability for long term planning is apparently not the forte of people who are concerned with short term profit, and I think that's what we're mainly looking at. Whether it's the government feeling obliged to try and keep the private sector running, or the private sector runnign the government, I'm not certain. Whatever it is, they're not doing a good job about it.
Meh, I'm not an economics expert. But to me it just looks like the US government has not had either wits or will to set up sustainable rules to the private sector and has resorted to respirating it by importing capita more and more from abroad, which essentially has increased the federal debt to the point that the US is - quite literally - owned by the world.
Of course, other shortcomings of said government - such as tossing said money back to abroad without getting nothing noteworthy back (like in cases of Afghanistan and Iraq) - and in general using it to stupid things in public sector is a different thing. The sub-prime crisis, though, is mostly private sector problem and it's full impact remains to be seen. That's yet another can of worms... 
Q: By private sector, do you mean businesses as a whole?
The problem I have with blaming so much on business is that the businesses which have the unfair amounts of power are also the ones who have the greatest stake and resources in keeping the state stable. Microsoft, for instance, has nothing to gain if the US goes under and a company from China (or India or Japan) establishes dominant share in the software market. Same for any company in GB or the rest of Europe, for that matter.
The people who don't have the resources are the people that usually get the underdog support. The small businesses, the groups of mob protestors, and so on and so forth. Those are the people who lack the capacity for understanding the big picture and the consequences of their actions, if for no other reason other than their inability to allocate as much resources to researching them as larger corporations.
For instance, there was a protest called "UC Nuclear Free" that called for the University of California to end its involvement with the US nuclear weapons program. The UC did end its involvement, and as a consequence, sole control of the labs was handed over to Bechtel and a few other private corporations. To, them, I suppose it was a success. To me, it seems like a complete failure for anyone who believes that there's anything wrong with nuclear weapons, or that there should be any accountability whatsoever, as the UC is, at least, a public institution. Who really won out in that situation? The students, who gave up any semblance of control out of moral outrage, or Bechtel, which (according to wikipedia) gains a near-monopoly on US nuclear weapons production?
And arms companies probably have the most to lose of any corporation, save for the fact that they would be highly prized in any kind of collapse. Obviously the US government is going to be highly critical of who's building the weapons that go into its armies, and isn't going to let them have any close ties with a country that it might consider subversive.
