I've found the same thing, shots taken by my grandfather in the 60's and remembered as something special, now look disappointing, and prove difficult to scan and print.

(Perhaps some of it is the memory of being amazed as a kid at color pictures on a screen. In the intervening years, film and equipment improved, our own photographic knowledge, skills and expectations gradually improved, while images generally, in print, television and movies were revolutionised in technical quality.)