its not unique to ford.
by all accounts alec guinness hated being remembered for star wars which of course was at the end of his career when he felt he'd done a hell of a lot of other good stuff in the years before. as far as I know, he hated/refused to sign star wars things for a long time. of course, he forgot the fact that the films gave him financial security cos he was on a percentage.
in a way, I understand. Guinness was acting from the 1930's, he had a huge body of work, and to be remembered for a 'fluffy fantasy' film must have peeved his classical sense of drama.
however, to me. liking him in star wars, drove me to seek out his other work and come to appreciate him as a fine actor.