It does go against their own interests when feeding animals is more likely to attract dangerous animals that attack tourists.
People don't always make the decision they know to be in their best interest. If they don't actually know what's in their best interest, then I'd say it's less an issue of stupidity and more about ignorance.
Attack other tourists. If you feed a duck then leave, you're not attracting a bear to attack you personally. You won't step in your own poo either. Somebody else will.
People don't always make the decision they know to be in their best interest. If they don't actually know what's in their best interest, then I'd say it's less an issue of stupidity and more about ignorance.