Here's some more by Ogata: there are several different versions of the text of Nozarashi kikô, all with slightly different titles.
It's not known when exactly it was compiled. It probably wasn't that long after Bashô returned from the journey, perhaps the winter of Jôkyô 貞享 3 (I think that's about 1687). From the fact that there are several versions of the text, it would appear that Bashô wrote them out as gifts for the friends that gave him a place to stay. Thus the contents are not so much addressed to a broad public audience; it's really just for his small group of disciples and patrons.
Why go on the trip at all? "Nozarashi = exposed bones in a field" was no joke - travelers often met with grave misfortune, so it wasn't really something you did casually. Ogata's theory is that during the Tenna 天和 (1681-1683) period, Bashô was working on devising his waka-like style: fûga 風雅, or poetic elegance. The journey was one way to put the theory into practice. Of course, his house had just burned down, and his mother had passed away, so there were other reasons as well. These things may account for the very sad tone of the work, especially the beginning.
I have to read more about fûga; I only really have encountered it in Buson's interpretation, but basically as I understand it it's about transcending the vulgarity of everyday life, and travel certainly could contribute to that.
Also, Bashô had a pretty good network of disciples in various places that he could count on for support, and there were food shortages and other quality-of-life issues in the major cities at the time, so the timing was right for building relations with people in the provinces. In other words, while he might have portrayed himself as being motivated by lofty ideals, he also has a financial incentive for making the journey.
By writing and circulating his travel journals, Bashô made travel itself closely associated with haikai. I wonder if it wouldn't have happened anyway, given the fact that so many of the most famous haikai poets ended up having to move from place to place to support themselves.
