You are right, it's profit over health. The price of sugar, rice, meat and corn in the supermarkets is simply too low, and profit margins too high. Capitalism in a nutshell.
With 30,000 premature deaths, and hundred thousands of children in hospital during the burn season in Thailand alone, burning fields for profit should be seen as a criminal offence and any company dealing with criminal farmers should have its license pulled.
The laws are in place.