It's more like being an architect and working with bricks and cement yourself. The author's argument is that sometimes an "architect" should do that. Agree or disagree, but it's certainly not a truism.
An architect might in fact design something down to the brick-and-mortar level, such that someone else assembles it to the actual building. That architect is working with bricks and cement, effectively at the design level.
That's the same as using assembly language, rather than poking binary/hex values into memory.