Interesting thread.
One observation I have had over many years is that when miles are accumulated over a relatively short period of time the majority of those miles are from highway or interstate riding which produces less wear on the overall drivetrain. If the rider was using the bike for inner city courier service I would not expect to see the high mileage with more repairs.
I've seen Voyager XII with over 200,000 miles, Ninja 650 parallels twins with close to 100,000 miles, Voyager 1700 V-twins closing in on 100,000 miles. What they all have in common is steady running down the highways and byways of America, and constant use without abuse.