"They didn't want to explain to me the things I wanted explained and seemed to find me personally irritating in addition to the standard amount of disgust I have become accustomed to."
"My fundamental problem here is that your species seems generally disposed to kill anyone else it meets, has done it twice and was working on doing it a third time when I showed up, and absolutely has to stop. While I very much wish that the prospect of having to stop wasn't so distressing that several planetsful of you have sucked themselves into black holes, it still has to stop. I am more than happy to leave any of you who can exist in the same multiverse as other sapient species alive and, even, eventually, alone, but it's very hard - considering your collective track record - to trust that you're going to build a stable culture which doesn't hold as a central value killing everybody it runs across. So I'm trying to figure out the moving parts of the culture this planet's recent revolution is trying to implement, so I know if it's safe to leave alone or if in a little while it will construct a war machine and kill some innocent people, the sort in the sphere maze or some new species you haven't encountered yet."
"...I think I understand," says Assistant Coordinator Sikyal Tegati. "And I think I understand why the previous representative was having so much trouble. The previous culture is something that every person in the world understands, so every explanation of the new culture relies on that understanding. But I don't think you have that understanding. Do you?"
"Right. I mean, I have a lot of documents but I've been running around trying to intercept people before they suck their planets into black holes so I haven't stopped to read them all."
"That's okay, there wasn't a lot of warning beforehand. So. To what extent should I believe that this planet, at least, is not going to launch any further attempts at xenocide, and why should I believe that?"
"The destruction of the previous civilization came about because they were unable to cope with an outsider they could not eradicate," the assistant coordinator says earnestly. "But there is no rational basis for the eradication of outsiders! The existence of any thinking beings other than ourselves is supposed to be a fundamental moral wrong, but that is the mindset that led to planetsful of people sucking themselves into black holes. We don't have to think that way anymore, and if we do, we'll die."
"That's very rational of you!" remarks Cam. "And how did you seemingly alone of your species in general come to this conclusion?"
"I've got a loose picture, but breaking quarantine is not a paradigmatic taboo among my people."
"My species is, some people who I consider part of my culture do though."
"...Maybe they have better immune systems than you, or fewer infectious diseases, or they reproduce faster."