Why were Irenaeus and Polycarp suggestion on what day Easter should fall on rejected by the orthodoxy?

Irenaeus and Polycarp both felt that the 14th day of the moon was the accurate day to observe easter, however the Roman church did not agree. They felt that it should irrespectively on sunday each year. Why were these early church figures ignored in regards to the appropriate day to observe easter and whey were the Quartodeciman observance labeled heretic?