Kerrigan slaughtered an innocent group of protoss on Kaldir for no valid reason. Kerrigan's only mission on Kaldir was to reclaim Nafash's brood. This was accomplished by the first mission when she found out that they were destroyed by the protoss. The only valid reason for her to stay into the second mission would be to get the hydralisk strain, to which my response is simply to go get it somewhere else. Hydralisks aren't exactly rare specimens. Dozens/hundreds of worlds infested, and this is the only place in the galaxy where you can find a blasted hydralisk? Ridiculous.
Lassara echoes these sentiments:
"You do not have to do this. You could leave. Be away from this moon before the Golden Armada arrives."
And Kerrigan responds with an illogical non-sequitur:
"I can’t run. I know that now. My enemies will never stop coming for me. All I can do is fight."
You came to THEIR planet, and so did the Brood Mother before you. To say that they attacked first is asinine, because any rational person would have also attempted to stem a zerg infestation to prevent themselves from getting overrun. The zerg have destroyed the entire sector, and people are not to blame for defending themselves from planet-destroying monsters.
To add insult to injury, Kerrigan pretends that SHE was wronged in some way:
"I justify nothing. There is no moral high ground here. Your people have killed billions of zerg. We are all covered in blood. There may be more on my hands than yours, but in the end we are both killers."
They "killed billions of zerg" because zerg are disposable genetic clones who have ravaged the entire sector and are only given enough intelligence to perform their required function of killing people. Of course they killed them; Kerrigan killed them too back when she was still a human. What the heck kind of argument is this really?
Even when Kerrigan comes to Kaldir as the primal Queen of Blades, the Executor's logic for attacking her is still "you should not have ventured so far from your main hive". A problem easily solved by leaving instead of perpetrating mass genocide. Fact is, the protoss are conscpicuously missing from both Wings of Liberty and Heart of the Swarm. The only time they show up in Wings of Liberty is to cleanse a planet that's by protoss space. They don't CARE about the ongoings of the Koprulu Sector, and they don't CARE that Kerrigan is deinfested. Everyone insists that they DO care, but nobody can provide evidence of it. The protoss already know that the zerg power structure has collapsed, because they'd be idiots to be ignorant of such an important event, and the evidence so far is that they did nothing. Thus, Kerrigan could have simply left, and nobody would have cared. Artanis will not launch a giant manhunt just because one colony saw Kerrigan... who is now gone. They could have done that back in Wings of Liberty on Ulaan.