Probably the "greatest" achievement of the PT government is that many Brazilians now take the word of criminals in plea bargain deals as true narratives for their country.
Very sad.
There are multiple evidences of how PT institutionalized corruption. Joesley's quote was only brought up due to the article's context.
To say that PT 'institutionalized' corruption is to deny the history of how Brazil (and pretty much every country) came to be ever since the first european set foot on its shores. Corruption is institutionalized, trying to account it as individual efforts is merely accepting a poor media-driven narrative.