[AFAIK]

Palm oil became popular with processed food producers because it had the best property of trans fat, a long shelf life, whilst avoiding the worst property, producing cholesterol. Despite large scale deforestation and habitat destruction in Malaysia and Indonesia oil palm may actually be environmentally friendlier than alternatives due to it having much higher yields per hectare.

[Godstud]

When people talk about palm oil, they aren't discussing it's impact on the environment, only its impact on people's health.