> however retrospectively, it did not justify the hundreds of hours I invested in this project.

Trying to extrapolate this conclusion to the entire "quantified self" movement is not correct. The issue is the time cost, not the act itself. If a trusted company came along (as if...) that sucked up this much data to allow you to answer these questions with minimal effort, I'm sure this would be a different story.

Anything at the fringes of tech with no tried and true solution requires hundreds of hours of effort. The author's conclusions are also personal, there are other styles of living and conclusions to be drawn that change the calculus on whether to do it or not.