Measurable Commitment

I was listening to a story on Marketplace concerning discouraged workers, those people who could, in theory, be working, but aren't currently in the market for a job. Interestingly, they aren't technically unemployed, and so the standard unemployment rate calculations don't include them. Marketplace correspondent Mitchell Hartman asked University of Texas economist Daniel Hamermesh why this is.

Their commitment to work is clearly less. They aren't looking in the last month, for whatever reason.

Leaving aside for a moment the vaguely insulting tone of Hamermesh's comment, since when is the idea of the unemployment rate to measure the public's "commitment to work?" I suppose that this would be a legitimate question for someone from the Bureau of Labor Statistics; but then again, so is why the unemployment rate only includes those people who are actively looking in the first place.