The thread about Royal Dornoch goes on for seven pages and counting, but a lot of it really seems to be fighting between
(a) people who don't see why the club couldn't leave well enough alone, and
(b) people who believe even the best design can be improved upon.
In the hundreds and hundreds of threads we've had on Golf Club Atlas about restoration of golf courses, the topic of preservation lies in abstract. Everyone here seems to be in favor of restoring great old courses, but most of them wouldn't need any restoring if they hadn't planted trees when everyone else did, or hadn't let Mr. Jones build his new tees, or hadn't let the green chairman tinker with the bunkering. In short, they might have been fine, had the members been content to Leave Well Enough Alone.
Everything in design is a matter of opinion, so there is no real way to prove one's case here, whichever side you are on. The one fact of the matter is that Leaving Well Enough Alone comes without cost and without risk, while redesigning a course comes with exchanges of money. As a wise man once told Woodward and Bernstein, follow the money, and you'll understand the story better.
It is possible to IMPROVE a course by changing it, but it is also possible [though much less discussed, because no one is selling that point of view] to SPOIL a course by changing it. There are plenty of examples of each, that many of us would probably agree with, even though it's all subjective.
To illustrate, let's each name an example on each side of the coin.
My input:
IMPROVED: Rye, England
SPOILED: Wentworth (West)