Hero?
Namikaze Minato was a hero according to all of Konohagakure. He was a genius they proclaimed, and the Yondaime Hokage. He was Konoha's Yellow Flash; enemy shinobi had a flee on site command when they were confronted by him. Most importantly he was the hero that saved them from the Kyuubi no Youko.
Namikaze Minato however did not view himself as a hero. Inside the shinigami's belly he could see the world going on without him. From the belly he knew he wasn't a hero, but instead the worst father ever. His son was despised and alone. Kushina wasn't there to supoort him, and the villagers hurt him emotionally and physically when no one was looking. He wasn't a hero no matter what anyone said because he wasn't keeping the monster at bay.
To Uzumaki Naruto the Yondaime was a hero and an idol to him all his life. Granted he felt hatred to the Yondaime when he found out he was the cause of his problems. However that went away when he realized it helped him save his friends when no one else could. That and it healed him too. To Uzumaki Naruot the Yondaime was a hero even if he had caused him pain.