Trans fats are almost an entirely human produced product. Trans fats are not found in large quantities in any natural, unprocessed food. Trans fats are a product of lower production costs and expense cutting by corporations. The population would benefit if trans fats were banned in the future, making it impossible for companies to use them.
Trans Fat should not be banned. They are not healthy for humans but many foods in life are not healthy. It should be left up to the consumer to decide if they want to eat them or not. If enough people stop eating them they will go away on their own. For there to be a ban takes away freedom of choice.
I admit that while trans fats are far from what anyone would consider healthy food, they are not inherently bad if eaten in moderation. It's not so much the trans fats that are causing obesity and its related problems, but the foods that are being cooked in them and the serving sizes. Americans are not going to get skinny by switching to French fries cooked in a different oil. In fact, since any oil they switch to will be perceived as being healthier, people will more than likely eat larger servings!