I hear you, but some of these things (yardage books, long putters, etc) simply didn't exist for hundreds of years of the game. No one had even dreamt of them. Why are they allowed in without any underpinning or presentable/reasonable fact other than one guy figuring out a loophole to make things easier for himself?
I certainly don't begrudge anyone who thinks yardage books are perfectly within the spirit of the game and should be 100% legal for all-time, but my opinion is that a point could just as equally be made that they aren't and they shouldn't be.
Mark, I can't answer why something was allowed in before/since our time...why steel shafts, why gloves, sunglasses, why rain gear, why massive scoreboards that allow the competitors to know their position on the leaderboard (which Vardon didn't get), why (when) was the course/hole yardage ever known, why identifying numbers on the irons... but yardage books, even green books, are part of that flotsam...
The game has never had a pure essence, it's been about the better mousetrap since its birth, in fact, perhaps the most seminal rules/plays contretemps is the break between Old Tom and Alain Robertson, when Robertson had the monopoly on the featherie ball and discovered Tom was using the guttie....
off to Prestwick with ya then laddie!
So, no Mark, and your last sentence is what I resist the most, there isn't (IN CONTEXT) a legit 50/50 or even 90-10 split of pure opinion available here...you either recognize/challenge the empirical truth Kuchar's caddie speaks (no discernible advantage) or you have to examine
any/every evolution of playing the game in such a light. Neither side gets to claim rightful purity.
"Progress has never been a bargain, you have to pay for it. I think somewhere there's a man who says 'Mister, you want the telephone? Ok, but you lose the charm of distance and privacy...Madam, you may vote, but at a price - you can no longer retreat behind the powderpuff and your petticoat...Mister you may conquer the air, but the clouds will smell of gasoline and the birds will lose their wonder.'"
cheers vk