We know why it's in foods. It's cheap. It's really cheap. To make sure that choice is clear, labels would need a requirement that any amount is listed... and not allowing the "less that .5 gram" exception that exists today.
Of course, there's a part of me that knows that people won't think about any consequences anyway. I weigh freedom which allows increased public health costs (medicaid, medicare, Social Security Disability, whatever else) of allowing this choice, vs an outright ban that might make that serving of Oreo's cost an extra 10 cents a bag (no citation, it's just a guess). I honestly don't think there's a correct answer in this case.
I don't think it's a major violation of our rights to ban a substance that was designed to be redundant if it's markedly more harmful than the existing alternatives.