Just a theory, but I've decided that the position of Mr. Olympia is so lofty that it cannot be won on your first attempt at it. Dexter could have been assumed the winner last year IMO, and a good argument could be made for Phil actually having bested Dexter this year. Jay could have won it from Ronnie one year before he actually did. I think it takes one year, minimum, for the idea of a guy being Mr. Olympia to become popular enough in the public consciousness before a competitor is actually enabled to take the title. I also think that by the time many of these guys take home the Sandow they are on the brink of their competitive decline. Physiques have a "fresh" quality to them when the competitors are coming up that after a few years of competing first fades, then sort of "grow stale," and then finally you begin to see signs of "wilting" when they are on their way out, like the subtle ones Jay demonstrated last night for the very first time, such as wrinkles over his left nipple area and the pronounced ones in his low back. These were tale-tell signs for me that he was done. Last year he wasn't "wilting" so much as he has a "stale" look to his physique. Kinda like it was just chemically patched together for one last win. I'm not sure that Dexter brought anything "fresh" to the table last night, and Phil Heath looked to be in the prime of his life; his physique alive and fully popping.
Now think back to Dorian Vs. Levrone in 1992. Dorian was able to win the title because he had come so close to Haney the year before. People had had one year to consider the notion that this guy would be the next Mr. Olympia. Levrone, looking back at that competition, was for many people viewing the YouTube clips today, actually much more impressive than Dorian that year, but very few were ready then for this relatively unknown to come in from out of nowhere and take it. I think people, as a whole, might be reluctant to just give a crown like this to someone who could prove to be a one-shot wonder, and need to be reasonably assured that this person is duly qualified to serve as such an important figurehead and ambassador to the whole sport.
This theory helps explain why the Mr. Olympia title has been so controversial over the years. Thinking on a broader scope, you could also extrapolate these ideas onto the presidential campaign and consider the consequences there.