I hope this is open minded enough for you.
It should be noted that the high doses of Vitamin C being administered in New York are being given intravenously, not through the stomach. It is also being used for the critically ill - when someone is fighting for their life side effects of their treatment may be considered the lesser of two evils.
Vitamin C is believed to assist in fighting inflammation, thus supporting the immune system. BUT only small amounts of Vitamin C, less than 100mg, can be absorbed by the body at any one time, the rest is expelled in urine.
Large amounts of Vitamin C can also lead to diarrhea.