Why is it relevant what he does for a living? It's his passion and hobby that is interesting.
> Why is it relevant... I'd say the point is "An Ordinary Guy did X". Vs. an engineering genius, or somebody with deep pockets, or a Hollywood special effects model builder, or 3D printer junkie, or whatever.
"Engineering genius" not being an "ordinary guy" is a kind of classism. The whole tenor of the "truck driver did something interesting" is essentially classist thinking.