@linrey it was not just the pain implants per se, it was the attitude of their creators forcing those on them and abusing its use like the Kaylon were mere toys. Had the Kaylon deactivated the pain implants, I'm sure the "humans" of that planet would have found a way to update those, come up with a new version or even come up with something far, far worse and sadistic. The abuse wouldn't end, so the Kaylon had to react harshly to make sure it would stop.
Sure, there's always the diplomatic route, resolving matters through conversation, but since that race clearly didn't acknowledge them as anything else than robotic slaves, I doubt the diplomatic road would have paid off. The Kaylon even asked for freedom and it was denied to them.
Shout by LeftCoastBoomerVIP 2BlockedParent2022-07-15T02:46:36Z
(spoiler) It was a weak defense given for the Kalon genocide of their makers. If pain was being delivered to them beyond all reason, why not just deactivate the pain response? Seriously, this was a huge overreaction. It certainly didn’t elevate them morally over those they slaughtered in their sleep.