Well, quite simply, John Smith is a big fan of settling the New World. I have to admit that your question made me smile because John Smith is certainly not a historian (or perhaps I should say that if he is a historian, he is certainly one with his own interest at heart). He is a grandiose, ostentatious person from England out for his own gain just like all the rest.
This purpose is apparent in his attempts to convince other British citizens to move to the New World in the advertising piece of complete propaganda that you ask about in your question which the full title is as follows: A description of New England, or, Observations and discoveries in the north of America in the year of Our Lord 1614, with the success of six ships that went the next year, 1615.
First, let’s keep in mind that full title in John Smith’s attempts to convince his other British citizens to help colonize the New World. John Smith lets us know that it is a “description” which leads us to believe his statements and “observations” are fact. He discounts the harsh conditions and harsh travel to reach the destination completely worth it due to what the colonists would find:
In the harbors we frequented, a little boy might take of....such delicate fish, at the ship's stern, more than six or ten can eat in a day; but with a casting net [we took] thousands when we pleased.
What he describes is a land rich in natural resources, ripe for the taking. In describing these, he is not only indicating things such as lumber, fish, and game, but also precious metals such as gold: the main pursuit of his employer, The Virginia Company.
Through this “work of literature” John Smith promotes himself as both tour guide, adventurer, and explorer. The irony is that John Smith included maps in his work. These maps were, in fact, accurate and, unfortunately for Smith, this rendered himself basically useless to new settlers (except in the realm of convincing them to settle there through his writing). Further promoting himself, John Smith continually invokes God (even in the title).
[We are] planting and building a foundation for His posterity, got from the rude earth by God's blessing in his own industry, without prejudice to any.
In further promoting himself, John Smith kind of taunts new settlers into coming by trying to get them to prove otherwise.
In conclusion, it is also appropriate to mention how John Smith tweaked the truth a bit in his story of Pocahontas in a different piece of literature where she “laid her own upon his” in order to save them all. Still, John Smith does supply some much needed background of the area (and its native inhabitants) so that new settlers could succeed. In short, John Smith is a promoter of the Virginia Company prone to exaggeration whose attitude toward settling the new world is one of no less than complete affirmation.