Because the plot is retarded. Not everyone knew Naruto was Minato's son only very few knew that his kid was Naruto. But for some reason, Kushina wasn't hated or exiled at all for being the nine tails jin like Naruto was.
Minato hoped sealing the kyuubi in Naruto would make him a hero in the eyes of the villagers, but they just saw him as the demon fox who attacked their home and took their Hokage away. Not to mention Hiruzen/Kakashi/Jiraiya not taking care of orphan Naruto.
Hiruzen did the most but we don't really what he did for Naruto other than watch him though his crystal ball.
Minato hoped sealing the kyuubi in Naruto would make him a hero in the eyes of the villagers, but they just saw him as the demon fox who attacked their home and took their Hokage away. Not to mention Hiruzen/Kakashi/Jiraiya not taking care of orphan Naruto.
Hiruzen did the most but we don't really what he did for Naruto other than watch him though his crystal ball.