Orangutans Smoking?

I couldn’t believe it when I first read it in the the Guardian but yet, this is an orangutan with a bad addiction.

Tori, the 15-year-old orangutan has been smoking cigarettes at the Indonesian zoo for a decade as a result of people throwing them in her cage over the years. Visitors continuously would throw lit cigarettes into her cage to watch her smoke them. Finally, after 10 years of this nonsense the zookeepers are planning on removing her from the zoo temporarily to help her break the habit.

My question is why wouldn’t they make the cage enclosed the first time Tori began smoking and was being taunted by the visitors. It is unfortunate because Tori thinks she is putting on a good show but she doesn't realize the harm she is doing to herself.