Why is taking such a long time for China to eliminate melamine tainted milk from the supply chain?

The incident in 2008 was resolved two years ago. You are referring to a new and separate incident that surfaced this week. Food and pharmaceutical safety are top priorities in China, Europe, America, and around the world. The reason the melamine problem was discovered is thanks to government oversight and coordinated reporting from relevant medical authorities. China's agricultural and health authorities are doing their best to ensure safe products for everyone. Tainted products are not unique to any single country. The American pharmaceutical giant Johnson & Johnson repeatedly recalled its children medications over the last few years. Over 60 million bottles of Children's Motrin, Benadryl, and other J & J products were recalled in 2008 and again in 2010.