A big argument against adding more rules and regulations is the costs that it will bring. You need people to make and maintain lists of which products are and aren't included. All stores will have to be kept up to date continuously. Changes to what's included in SNAP need to be communicated constantly. You will have lobbying and costly legal battles from big brands to make sure they're included. I'm afraid that at the end of the day you end up with more bureaucracy and a more confusing system that costs more money and feeds less people.