He isn't really a developed character. His actions don't make sense most of the times and his goals change from left to right.
As for people hating him, I blame Kishi. If he didn't force this vomit inducing bromance the hate would've been less intense. But no, you have Sasuke do kitten here and there, and Naruto is waiting and ready to forgive him with open arms like the love sick puppy he is. People would rather wish Sasuke to die in comparison than having this whole manga centered around him, an unattractive guy the reader can't sympathize with.
Yes The Bromance is utter kitten in here its unbearable to see it being shoved right in your face constantly and its what makes this manga not be one of the best everyone are tired from it bc it makes no sense by the way its written Naruto would have been so much better as a story if we didn't have this so much sign .
I still love the story and want to see how all of this resolved but it isn't what it used to be , oh well nothing we can do about it .