Dude Itachi had insane amounts of potential. He sacrificed all that for his village, his brother, and the shinobi world. If he truly was the evil psychopath we thought he was, he couldv'e easily mind**** and make sasuke form MS just to take it and acquire EMS. Itachi's only weakness was his lack of chakra and stamina which could've easily been solved by injecting himself hashirama dna. If itachi wasn't a hero I truly think he could've easily surpassed Madara and maybe even Hashirama.
So what you're telling me is that he wasn't smart enough to inject Hashirama DNA? I agree
If he had potential enough to rival Madara's power, he wouldn't have needed to sacrifice everything, kill his own clan, and ruin his brother's life. If he obtained rikudou mode or even the rinnegan, he could have easily stopped the Uchiha rebellion without the need to kill.
Madara was able to fight an army easily with only Katon, taijutsu, Susanoo. Itachi has all three....yet he can't defeat the Uchiha and one village.