Well, I've been gone to Tucson for the day and wow, what a bunch of misguided conversation*. Let me just focus on the notion that "a par-3 cannot be considered as the greatest hole...", as this clearly is a dangerous thought.
Bunk.
The greatest hole should be one which embodies a bit of history, charm, excitement, strategy, and involves a variety of playing conditions by way of its position on our natural earth. It should also be beautiful, strike a chord in the heart, be amazing in terms of blending nature with our beloved golf, and it should stimulate the sensations of all men and women who visit her tee. It might also be that the greatest hole is one in which play could possibly result in a score of just one (this being among the most cherished of a golfer's life of stories), or perhaps twelve (this being also among the most cherished of a golfer's life of stories.)
It should test nerves, strength, mind, spirit, body, vision, and one's desired degree of risk-taking at a given point in time. The best hole in the world must be fun and enjoyable. It should be a magnet, attracting all who have ever play golf to want very much to join it, even if just in a book, on TV, or by way of admiring a framed snapshot of a lucky fellow who got invited there once to enjoy a round. Like any attractive subject, it might be slightly hard to catch which makes it even more alluring.
It should ideally be devoid of any civilization so as to truly catapult a golfer into nature, from where golf began and where it will end. It might also be at the literal end of the earth, or so close that we feel like we might be there.
You see, these qualities -- even if you disagree with more than a few -- have not so much as a grass blade's worth of value to the concept of par. It does not matter how many shots we take to reach home, or for that matter whether we play the hole forward, backward or just walk along its fairway late one afternoon and meet someone coming the other way doing the same; both with not a club, nor a ball, but just the love for this earthly pastime we have come to embrace.
*Not all of it, just some.