"It's a bit hard to believe that. in a world with so many bad films, a good film can be overlooked or forgotten, especially if it was created by first rate artists, but it does happen.
Sometimes film makers go out of fashion and even their best works can be swept aside. Sometimes a film maker is perceived as making a certain type of film and anything that's an outlier to the auteurist theory crowd can be put to the side for the sake of continuity. Quite often, a film maker is loved by the select few and, no matter how good a film is made, it won't get known widely.
Sometimes autumnal works of even great film makers, perhaps lacking the spark or energy of earlier works but gaining in depth of maturity, are pushed aside for those of newer and more immediate artists. Conversely, good early works by those yet to achieve greater fame are forgotten."