Greenpeace activism against golden rice in the Philippines is the quintessential case study even though it's adjacent to environmentalism. It displays not just cynicism but the abject cruelty - mass death and bodily harm - that these disgusting activists are capable of inflicting on the world's most vulnerable people.
Why is it harder to supply people with vitamins than to supply them with seeds that require advanced engineering? Will the golden rice stay golden without careful breeding? Someone is cynical here.
Because getting special seeds into the hands of a few farmers is feasible, but getting vitamins into the hands of millions of extremely poor people and getting them to change their habits is not feasible. These people already eat rice and the distribution of rice to them is already established. They don't have to change a single thing.