This is just a personal theory, but hey, it makes sense:

One hundred years ago, or even fifty years ago, the average reader did not travel widely and did not have access to full-color photographs or television. They had never seen pyramids, or elephants, or tropical rain forests. Many people had also never seen a prairie, a pine forest, a stretch of English farmland, or an industrial city. This means that the reader's repetoire of pre-conceived images was not as vast as the modern reader's.

Description was inherently interesting because it took readers somewhere they'd never been before. Description was also necessary because brief phrases like "whitewater rapids" or "towering cliff face" were not sufficient to call up any pre-conceived images.

In general, modern readers still like description, but their taste is different. They like their description in bits and pieces, interspersed around interesting events. Or, if a full paragraph is to be devoted to description, they expect it to do more than simply describe the landscape--they expect the description to cause them to view the landscape in a new way, or evoke new insights into the story, or both.

This is not to say that long descriptive paragraphs are inherently bad, or that there are no readers who like them. But as a rule, modern readers come to the page with vastly different experiences than readers of the last century. This is why "But [insert classic author] did it!" is not a valid justification for opening a story with five paragraphs of weather and landscape.