If the experts and lovers of golf course architecture and magazine writers and top flight players of the 1900s, 1910s and 1920s were right that the then-new courses like Myopia and Garden City and Oakmont and Pine Valley and Merion were great courses , and if every one of those courses (and a dozen more) was so deemed precisely because they were long and hard and true tests of golf for the very best golfers of the day, then why would we ever suggest/believe that modern-day experts and lovers of gca and writers and pro golfers are wrong when they praise as great the now-new golf courses precisely because they are long and hard and true tests of golf for the very best players of the 21st century?
Peter
I don't think the premise is supported by history. The courses listed weren't necessarily exceedingly long for their day. A few were quite short. While it was reported as longer, I'd be surprised if the Merion East even 6000 yards when it opened. And not all the courses listed were considered hard. Oakmont originally was considered quite easy, which is one reason it was eventually made hard. And not all the courses were originally considered to be great. Oakmont is again a good example. Sometimes the greatness classification came over time and was sometimes very much related to repeated use for tournament play. Pine Valley was considered great before it was even open and it was apparently built with the goal of challenging the better player, but even Pine Valley wasn't considered exceedingly long.
During the time period in question many or most of the best minds in golf (MacKenzie, Darwin, Macdonald, Colt, Whigham, Hutchinson, Low, etc.) knew that there was a lot more to a quality golf course than just length and difficulty, and this was reflected in the golf architecture. If there is a similarity between now and then, it may be that some of the designers today are coming to similar realizations about what makes for a good golf course.
I am not saying those courses were easy. But length and difficulty were not their defining characteristics. Some were considered great because they were interesting, exciting, and beautiful.