Why? There isn't any particular difficulty of getting old working cameras for people who want them. One 80-plus-year-old Leica more or less won't make any difference. So we save a few for historical interest. Is that such a bad thing? I was in New Orleans a little while ago, and saw Sidney Bechet's saxophone in a display case. No one was playing it! Did I worry about that? No. No one else playing it was going to be Sidney Bechet.
One gem of a gentleman. Do you know Life kept his office for him until his death although he was no longer productive.
Chuck Yeager who broke the sound barrier in 1947 was allowed to pilot a current jet fighter thru the sound barrier one last time a few years back. He did have an escort and did not push the fighter hard.
I am not surprised. Some people just manage to keep their gear pristine for decades even if using them constantly, whereas some others wear them down cosmetically in a couple of years.
Sort of along the same idea, as a teenager, I liked to hang around a garage that raced midget racers on weekends. Monday morning the racers would be disassembled and CLAd, usually by the garage owner. He always worked dressed in white with his sleeves rolled up. I never saw him get any oil/grease on anywhere but his hands. Not a drop on his white clothes. He took pride in that. It is quite possible that Eisenstadt took pride in keeping his equipment as new looking and as clean as possible. I have known of other photographers who would try to make their equipment look as scruffy as possible as they thought that made them better photographers. Something to think about......Regards!