I think that people have in mind a "golden past" that gives them the motivation to use or collect old technology. Not that it ever really existed. It's more of a state of mind.
I love old cars, motorcycles, aircraft, boats, bikes....It's funny that car collectors for the most part cut off the desirable cars at the year 1971 (with a few exceptions)- the year many things changed in the car biz. With aircraft, it's the "Golden Age of Aviation"- mostly pre-WWII planes.
With bikes, it's what you rode "back then" I think. That's the reason '80's bikes are popular on this forum.
My $.02.