The devil is in the details (of the article). Some were punished and some were not. The early Nazi party financier mentioned in the article (Hugenberg) was able to walk back all his charges, get back all his assets. For I.G Farben (chemical manufacturer), it mentions, 23 of 24 were charged of war crimes, 13 were sentenced.

Regarding treating the corporation as a single entity (versus treating it as a composition of ppl), their ideology and power still lives on. Krupp's (now part of ThyssenKrupp) owner was too ill to stand trial, though his son did, oddly enough. It still existed within the Krupps family, even after things had settled. It needs to be seen from both the composition lens and the singular lens to make sense