When discussing Johnny Appleseed and the merit of his actions, one must remember that apples suitable for eating were not available during his lifetime. Until about 1900, when a tree that produced sweet apples was found, grafted to other trees, and widely distributed, virtually all the apple trees produced sour, inedible apples. Due to considerable genetic variation in the seeds, the probability was extremely low that the seeds of a tree that produced good tasting apples would also produce good tasting apples.
What, then, were apples used for, if they were too sour to eat? Cider. And this was before pasteurization and refrigeration, so apple cider quickly turned to hard cider.
Johnny Appleseed promoted the expansion of the frontier by providing cheap alcohol for the masses.
Note: I feel a bit embarassed about this, after reading DejaMorgana's writeup. I meant this as a purely factual wu, with a bit of an edge. It is based upon my reccolection of the second hour of NPR's Science Friday (http://www.sciencefriday.com/pages/2001/Nov/hour2_112301.html), with guest Michael Pollan discussing his book, The Botany of Desire: A Plant's-Eye View of the World, as well as discussions with a biology professor. These are my recollections of said discussions, which, given the writeup that follows mine, may not be as accurate as I had previously thought. Because the computer that I am using presently does not have any working audio capabilities, I cannot listen to the show. I will be checking Pollan's book out of the library in the next 2-3 days and updating or nuke requesting the writeup at that time, whichever seems more reasonable.