I think you're entitled to derive some monetary benefit from your writing. However I support the decision to make the book creative commons. Perhaps offer paid versions in some form (audio, epub etc.) or use it as a platform to build your list (which I see you're keen on doing) and seek out speaking opportunities.

Oh, and it probably isn't shitty, based on the strength of this article. I'm assuming there will be some light-cringing involved if engineers read it, but I may be wrong, and I'm sure there's a huge audience for this out there. I know self-help stuff gets a bad rep. Completely understandable most of the time. But there's probably a reason it's so popular - i.e. the good stuff is good!