The side characters all add fun, atmosphere, dialogue, support, variety of jutsu, strategy, plot and background. Without them, I wouldn't even bother reading one more page. I would never have watched one more episode of the anime if it was Naruto vs Obito or Madara or whoever the only 'real' characters are that people here hold so dear.
I don't care how much everyone adds power wise. I like them around and would find the story poor without them. Instead of constantly powerupping Madara, Sasuke and Naruto, Kishi should massively work on the side characters so the fanboys and haters would have something else to complain about. But he can't focuss on everyone at once.