I also think Naruto deserves some sort of closure about his feelings for Hiruzen; she clearly felt inspired by him and adored him. However, Hiruzen wasn't a really good person. I think the problem is that he rules too long, is too soft to his close people who break the law like Danzo and Orochimaru, and his advisors are as old as him.
Hiruzen could not change the system because he felt the old system was right while the world was changing; that's why Konoha could fall into chaos. And I think the reason for Asuma's poor relationship with his father is because he (who is about 35-40 years younger than Hiruzen) saw that his father had to start changing the system following the dynamics of the world. Still, Hiruzen didn't want to listen because he believed in his beliefs, and his way of running the village all along was already correct.
And in my opinion, about the system failure issue regarding orphan handling--Hiruzen belonged to a clan, never growing up alone. If there are orphans, the clan will usually take care of them. Growing up in these privileges, Hiruzen had no idea how clanless ninja children who had absolutely no family other than their parents would grow up as orphans and take care of themselves; he assumed they could just do it and endure and leave them hoping they would be loyal ninjas till the end.
It's interesting how an adult Naruto (after going to therapy!) realizes that this system of handling orphans is terrible, awful, and wrong and that it's not normal to leave a six-year-old to raise himself in an apartment, to cook and do laundry and take care of his own money, even if he insisted he did, that a responsible adult should be able to give him a safe place to grow. The orphans are under Konoha's protection, and as such, the Hokage's protection and Hiruzen have failed to carry out his duties. He had participated in making Naruto's childhood miserable.
I thought Naruto would feel a little sad and betrayed, knowing he deserved something better for his childhood, but he couldn't get it. And Naruto will start to see that Hiruzen is an ordinary human who has many faults; not the Hokage, not the God of Shinobi. He had disappointed and harmed many people, failed to unite peace within Konoha's own walls, and so on. I like to think Konohamaru also grew up finally seeing his grandfather as a man who can and has made many mistakes; this man was not perfect.
There was a post on Tumblr about Naruto and Konohamaru talking about Hiruzen as they grew up and overcoming their feelings for Hiruzen; that's a good post, but I failed to find it again hahaha.
I like to think Mirai grew up with accurate, not-covered-up history. She learns to fond Hiruzen’s memories because, after all, he was her grandfather, but she will never adore him (or his choices). She admits that he was not a really good man despite his gentleness facade, more of a good Hokage/grandfather than a good father (how angry Asuma was at his father that he won't want to be in the same location as his father? I think during the tense period of Asuma and Hiruzen, people were separated into two camps, hahaha, and the staff at the Tower often gossiped about their Hokage and his rebel son).
For Iruka, I think he grew up separating the Sandaime and Hiruzen personas in his head. Hiruzen was the one he loved for comforting him after his parents died, but Sandaime was the Hokage he had to obey, the one he secretly cursed for failing to properly handle the problems of orphans.
