Corn is deficient is lycine, which becomes available when treated with lime, as in hominy, or mixed with legumes to provide complete protein. Almost as soon as corn was developed as a crop,
native americans learened to treat it with lime or mix with complementary protein. So i do not see it as a poison or problem when used properly
A bigger question is if it is
sustainable to grow. I know organic farmers that grow corn in rotations that build soil and produce good crops. Compost, legume rotations when used at the right scale can allow corn to be a valuable crop