People are constantly coming in the nursery where I work part-time with pages printed off of websites, ripped from catalogues or, worse, torn from the pages of home improvement magazines. Some newbee gardeners will willingly spend thousands of dollars buying plants from catalogues or websites only to find that the plants just don't do well here. Because they seldom have any foundation knowledge about soil, light, moisture, zones, or the needs of plants, the plants die. The surprising thing is that these folks are often only a generation or two removed from farmers who understood all of these important factors.
With great joy I try to help those who want to learn. Before I will sell them any plant life, I send them home with a good book or website (like DG!) I ask them to measure their yards, test their soil, talk to gardening neighbors, and draw up a list of plants based on what they are learning. They become better gardeners from one year to the next. They kill fewer and fewer plants every year, spend less and less money replacing plants, and become happy and successful gardeners.
Those who don't want to learn tend to become cynical serial plant murderers. Eventually they give up on doing any garden work themselves and either hire landscapers or move into condos.