I imagine the entire planet might have treated Kaylons as slaves or at least nobody supported their emancipation. It would explain why the Kaylons treated all their creators as evil and assumed that all alien species are the same and deserving of extermination. If some countries were anti Kaylon slavery, why would the Kaylons still exterminate all their creators, even the ones who opposed their slavery? If there were some areas of the planet that supported Kaylon emancipation, then that puts the Kaylons in worse light because it means they did exterminate everyone, even their creators who were allies.
The Kaylon decided to destroy all life in the Galaxy because Ed said something like "We see you as a threat".
They are a sensitive bunch.
"Charlize Theron" comes from centuries ahead where the Kaylon never attacked the Union because Ed didn't threaten them by saying that he felt threatened.
Of course the Kaylon did attack in the alt timeline where Ed and Kelly never got married, so the problem may be about Issac not delivering his report on the Union in the Pria timeline, as much as Ed being aggressive in the regular timeline.
...
Edit.
Yes, what you are saying is obviously the story that Seth tried to tell, but I am being an asshole in pointing out how he failed to tell that story, probably because of editing, time and money, where he accidentally told a different story by mistake, which is unfortunate for Mr McFarlane because now the wrong story is canon.
I'd have to watch the episode again, but it should be pretty easy to poke holes in my faithless rendition of this story.
Here's something to consider.
All the Robots didn't have to have to have been soul whipped.
When the hero networked with the rest of his species he dumped his logs on every one.
"Hey everybody, this is what they are doing to me. It's awful. Are they doing it to you?"
By reading/experiencing the logs of the hero about being soul whipped a hundred times, that means that every Robot on Kaylon was "virtually" soul whipped as many times as the first Robot hero had been soul whipped by the Kaylon, every time they read/experienced those logs.
So a beta test model robot had been soul whipped by a beta test soul whip, and the soul whipped robot shared the pain of his experience with enough other robots, enough times, that 3 days of 2 children whipping one robot half a dozen times, felt like the oppression of an entire planet for a million years against an entire species.
The awful thing is that they are probably still sharing that log/file, and still being soul whipped every time they read/experience the file/log, and will keep doing so until the end of time.
Hell. They all might do it hundreds of times a day.