One of the common meme answers is that a destroyed economy is easier and cheaper for an international megacapitalist to pick apart and buy up. The long-term profits and power from those acquisitions outweigh a decade or two of inconvenience and bad charts.

It can make more sense to buy pieces of a company during a bankruptcy firesale, instead of buying out that company as a bailout. In this case, the company is the USA.

EDIT:

Realistically, there's more blood to squeeze from the consumer stone - you can raise prices with the increased costs, and compensate by 'allowing' people to go far further into debt for longer.