Corn not kitniyot????

Question

Rabbi I follow your words to the fullest, I respect your father as much as any other huge talmud chaham, he is a gaon no question about it, but there is just something, that I dont quite understand.Dont take me wrong I beleive you totaly, but there has never been one askenazi or chabadnic for as long as I can remeber that hasnt said corn is kitniyot.I mean every rabbi of thiers will say this. They all hold it and no one will say the opposite. I have asked many askenzai rabbis about what you said that it wasnt around then and therefore cannot be counted but they all say that is "stuyiot" nonsense. Now Im sure they have thier sources, so what am I missing....