Basically the long and short is that corn is a good and healthy crop if it is grown correctly and non-gmo, and you are not allergic. FWIW, my dad is terribly allergic.
The bad about it is that it is not farmed well, it has become a "junkfood crop" and is in everything. Corn is now making it's way into plastics, it's already in gasoline (which is why some Jewish communities get corn-free gasoline for passover), it's in drinks, it's in food, it's in junkfood, it's in packing peanuts, in wax covering, paper products (TP, Paper towels, baby wipes, disposable eating utensils/plates/bowls), it's in styrofoam now (packing peanuts and eating utensils), it's in the coating on those nice little paper containers for things like milk and juice, it's now in plastic wrap (reynold's and such) and they're finding ways to make it into clothing.
That much corn can't be good for a person.
Traditionally, corn was a fermented food. That stopped somewhere in the 40s-50s, except in cultures where people continue to eat traditional foods. There was a story in the 30s-40s that kept cropping up in the south about people who were not eating fermented corn and were subsisting on the stuff and had
Pellagra - basically nothing but vitamin B3 deficiency from terribly poor nutrition. (corn and pork fat)
See this also.
The question really is, will our food be used for good? (Best optimal nutrition / non gmo) Or will our food be used for bad? (Gmo, slam it in everything and anything you can and subsidize the heck out of it)