Nothing goes faster than light: rule of the universe. No artificial minds shall be allowed to live: rule of the People. For a galactic rotation we have been locked in battle with the Machines. Two exponentially-reproducing resource-using foes, in near stalemate. We’ll take any advantage we can get, because so will They.
One of our telepaths, relay station 4, spiral arm C, reports of a rising intelligence. A crude map of the planet, based on interference patterns from mental processes, is drawn (we would recognize it as Earth). Vast ships, grown rather than built, are dispatched to make contact and find new recruits. Time to destination: ten thousand years.
The ships arrive and awaken. They look down, with eyes and tree-like radio antennae. Preparing to welcome new intelligent organic life into the People. And then they recoil in horror: the ones on this planet are building machine brains. Traitors!
Not ones for cruelty, the People make it quick. The orbital bombardment vaporizes the surface in minutes.