Why does Soldier Lad sing about manual labour?

His song about being put to work in some factory turning a crank over
and over, although quite catchy, is just the kind of thing that the
African American community would be shying away from I would have
imagined. I admire his honesty though, and think the use of the same
refrain over and over certainly pinpoints the mundane and Sisyphean
nature of such work.