Sometimes the metrics of greatness are so clear and well defined that there can be no argument. Even 50 and 100 years later, and without any 'first hand' seeing whatsoever, I can know for certain and don't need any expert to tell me or support me in my belief, that Mantle's triple crown season of .350+ batting average, 50+ home runs and 130 RBIs was a GREAT season, or that Gehrig's 370+ average, 45+ home runs and 175 RBIs (while following Ruth in the order!) was perhaps the GREATEST season of all time.
But with architects themselves consistently telling us that greatness in gca is "subjective", and with the experts and wannabe experts telling us that we have to play a course not just once but many times, and in all conditions, in order to determine or even understand its greatness, we naturally come to think of greatness in golf courses as being a RELATIVE/COMPARATIVE assessment (and ranking), instead of an absolute or objective one.
They can say that all they want; I don't believe them. (And, in truth, I don't think that in their heart of hearts they believe it either.)