You know being emotionless and wanting to destroy the village/world/system is not what makes a character cool.
This is a shounen. That is always cool.
Why do you think so many people like Madara or Aizen? It's because they don't give a fk about anything else but their own goals.
Same with Sasuke during his MS days. People liked to see this change so we can have a chance for evil.
I don't know why so many people get constipated when Sasuke does something bad, as if a shoune will not have bad characters smh..
Also, I liked Chuunin exams Sasuke and Hebi Sasuke too. I am not saying that bad is always good, but in some cases it builds conflict which progresses a story.