Could it be that he and Soros are big buddies?
I think the reason is because like your article says Petrobras is state-owned. i.e. the loan to Petrobras is akin to a loan to the Brazilian government and is no different to the US government giving Pakistan money to strengthen ties with it or any other country as the government has done for decades.
Furthermore, the money generated by Petrobras is used to push money back into social programs in Brazil such as health care and public transport for the poor which is a better way to help the poor in Brazil than throwing US AID money at them the way the US does everywhere else, and will also strengthen the US's ties to the Brazilian people.
And lastly and most importantly - the balance of power in the middle east is tough right now and generally speaking those countries populations harbor a negative sentiment towards the US. It is very much in US interests to have another country in another region also be a powerful oil producer as it means the Arab countries could never gang up on us and either make gas unaffordable or weaken our military by halting gas supply. If that were to happen, since we financed the drilling, who do you think has the best chance of being first in line for Brazil's oil sales?
On the flip side of your question - Exxon Mobile posted a $34 Billion profit last quarter while gas prices have been at a historical high during a tenuous economic recovery. Do they do anything for the American people that should earn them a tax break from the American people? Why should they get a tax break when other American companies don't even though they are among the wealthiest and most self serving group of companies in existence?
Just remember if you're reading an article in the Wall Street journal then it's an article that comes from those interested in Wall Street issues. Almost every investment fund in New York is heavily invested in Oil Company stock because their profits and dividends are always massive. This article is Wall Street protecting Wall Street. Don't mistake it for anything other than a distortion of the facts. The US gave 5 billion to Pakistan even though we found Bin Ladin there, but this LOAN that we will most likely get back and is clearly in our interests from a foreign policy perspective is getting bashed – makes me wonder why they care…