Obviously, I strongly disagree, or I wouldn't be interested in the topic.
I think there can come a point where a setting's been milked dry. Not to the point where it's utterly impossible to do anything with it, but at least to the point where everything feels like it's been done, all the major areas are explored.
Yet, if said setting has a lot of cool ideas at its foundation, why throw it all away? Why not do some sort of "partial reset," such as via a major timeline advancement?
I can't at all get behind the argument that it's somehow "unfair" to the fans of that setting. After all, if the line simply ended, they wouldn't be getting new stuff either. This way, there's still new material. Some people will love the new setting, some people will borrow from the new stuff to run the old stuff, and some people will ignore the new stuff and only use the old stuff--but nobody has lost anything that they wouldn't also have lost if the line simply stopped.
Doing this can, when done right, allow a setting to continue to explore the aspects and details at its core, while changing enough that it's exciting and new again. And sometimes, starting a brand new setting isn't the answer, not when an old setting has some of those aforementioned core elements you want to explore. If someone tried, they'd just be accused of "ripping off" Old Setting X, and still wouldn't be able to take advantage of all the specifics.
(I'm speaking hypothetically here. I'm not going to weigh in on whether I think it was time for such a change to FR, at least not in this thread, since--as I said--that's a topic I want to avoid.)