Board Thread:General Discussion/@comment-2124931-20140312212608/@comment-732150-20140312223600

Way too few techniques with a known creator to justify a field for it. Also, just because Dai spent two decades working on it, doesn't mean he created it. Madara knew about the effects, so unless we learn that the reason he knows that is because Zetsu were spying him use it, Eight Gates were already known of and used before the ninja villages existed.