I think what really annoys me about the "power-ups" of Naruto and Sasuke, was the time-skip.
In all honesty, the two and a half years that Naruto spent training was useless. H didn't seem to learn anything that he couldn't have if he remained in the village.
He became more intelligent, he became more tactically efficient.
But technique-wise? He learned to make Rasengan bigger.
In two and a half years, that's all?
In that time Sasuke learns around ten, if not more, different ways to manipulate his Chidori.
He creates Kirin, an almost godly level destructive technique.
He signs a blood pact with the snakes, allowing him to summon them.
He learns a multitude of snake-like jutsus.
Improved his control of the Cursed Seal.
Now I know Sasuke's supposed to be a genius. But Naruto developed the Rasengan in a shorter time than Sasuke developed Chidori. Heck, he even did the same with Fuuton: Rasen Shruiken.
Am I supposed to believe that with that capability he only developed a small improvement on his already present jutsu, in two and a half years?
I think that's why people get annoyed. Sasuke was already immensely powerful after the time skip...then they had to go and give him MS and such as well. People struggle to accept it, and rightly so.