Maybe some things that were true in the 1940s aren't true now. The world is a qualitatively different place now than it was then, because:
1. computers replace people's minds, not their muscles
2. the machinery discussed in the article was physical machinery, which takes time and effort to manufacture and trnasport around the world. But software isn't a physical object, and it costs nothing to replicate a useful program a billion times and put it on every computer; therefore the extent to which software can concentrate wealth is a lot greater than machinery could.
1. computers replace people's minds, not their muscles
2. the machinery discussed in the article was physical machinery, which takes time and effort to manufacture and trnasport around the world. But software isn't a physical object, and it costs nothing to replicate a useful program a billion times and put it on every computer; therefore the extent to which software can concentrate wealth is a lot greater than machinery could.