There is no shame in looking for evidence to support one's assumptions and then finding it. Had these people whom you are convinced to have been "devout Christians" maintained that there was indeed a global flood, you would simply place them on the side of people like myself who supposedly represent a "disgrace to my religion." Why not try holding back on the vitriol and understanding that there is more than one way scientifically to comprehend reality?
They did maintain for a couple of centuries that there was a global flood. the change in interpretation was gradual and painful. Try reading some history before slandering people.