Sasuke has as much reason to hate Obito as Obito had to hate Madara. Obito used Sasuke in the same ways that Madara used Obito. Madara was so intent on carrying out his plan that he must have had a plan in case Obito had died. That being said Obito did weaken Madara and save Naruto's life. Sasuke and Naruto would not have met the sage if Obito was not around to save Naruto's life. They did not meet the sage because of Sasuke they met the sage because the sage recognized that Naruto's way could change things. So let's stop with the woulda, coulda, shoulda.
Sasuke as always is being true to himself and his goals. Even Kishi admits he's selfish. He will do whatever he has to do to reach his goal. If someone gets hurt along the way, so be it, he will move on. Naruto does have to understand that Sasuke will do whatever it takes to keep Naruto alive to complete their goal. If he has to sacrifice the others to save Naruto he will.
He will not deviate from what he believes he needs to do even if it means someone else gets hurt or damaged by what he does. That is what Kishi meant when he said Sasuke was "pure". Not good or bad he just is who he is and is not going to change for others.
