Because they're part of the old system.
In that kind of logic, he should kill everyone.
Nope, only the most influential people. If you shut down an organization, you dismember only the leaders, you go easy on the followers
yup they are a threat.
The people would most likely side with the Gokage, rather than Sasuke. And which again put them in a war .
So he doesn't want to take any chances, and thus will kill the Gokage..... Only issue is, that isn't a smart decision either..
Yea but only issue is that , when you kill the leaders you risk the chance of a "cycle of hatred", which is engulves the followers of those leaders.
Something Hashirama realized:
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So basically the Gokage aren't the only ones he gonna kill. He specifically stated anyone who gets in his way.Sasuke aware of the grudges people will hold. People hate changes because its not comfy(k12 for sure), that's why sasuke said revolution which it takes time
Thats the whole point. Sasuke doesn't want kages in the first place so if he does succeed there wont be multiple kages just 1 ruler.