According to the article, hunger is a factor stressing them out and making them more aggressive towards the boats, though as you note they don’t seem to want to

According to the article, hunger is a factor stressing them out and making them more aggressive towards the boats, though as you note they don’t seem to want to eat humans: «The orcas return to this noisy, polluted stretch of water for one reason – to feed. They specialise in hunting bluefin tuna, also highly prized by humans. The near collapse of bluefin tuna between 2005 and 2010 “has led this orca population to the very edge, with about 30 adults left”, says Pauline Gauffier, who has studied them.»