I don't see why "Kayak Bill" has to be considered either, or one or the other. I certainly don't see him as a "Slacker". That is a shalow label I think we can set aside altogether.
He may be a "hero" to me in the sense that he went and did what some people only talk about, and most never remotely consider.
Certainly an inspiration to me-- I confess that I've entertained romantic notions of "paddling away" from "it all", though without the experience, determination, and perhaps fortitude to make it happen as this man did. Most likely without the sincere desire as well- I like the variety that a modern life affords.
Very fascinating and impressive, though!