I love Vietnamese food
but I have never been to this wonderful restaurant.
I think hunting for food is not the biggest part of the problem. Animals are killed for use in traditional medicine and magic (which are often the same thing). If I'm not mistaken, a piece of gibbon fur is suspended from Cerjak's Musket. Gibbons are sacrificed for hundreds of years when it is required to escape from adversity (for example, during a lunar and solar eclipse).
Another part of the problem is that people in the mountains have no other source of income. The government follows the path of prohibitions, but at the same time does not offer alternative ways for a dignified existence.