During the 60's, and I don't know how long after that, the art world, as represented by academia, actively discouraged representational art. They wanted everything to be "cutting edge." Only problem is that what is "cutting edge," or to put it more prosaicly, "in style this year," is usually out of style a year or two later.
In times past, artists strove to make their work timeless, which is why the best of it survives and is revered today.
That's the way I see it, anyway.