What do you make of the use of the passive voice in the last sentence? (Your answer need not agree with anything shown in the Brian H prequels)

> "The target of the Jihad was a machine-attitude as much as the machines," Leto said. "Humans had set those machines to usurp our sense of beauty, our necessary selfdom out of which we make living judgments. Naturally, the machines were destroyed."
(from God Emperor of Dune by Frank Herbert, as transcribed on wikipedia https://en.wikipedia.org/wiki/Butlerian_Jihad )