First of all, I do think that exploring the parameters of pure evil and abuse in Gintama is extremely limited because first off, it's a comedy, and secondly - Sorachi likes to give us 'life lessons' on how to proceed in the face of hardship. If that's not your cup of tea and you're not able to differentiate between a show whose themes revolve around 'rising above hardship' and 'being true to yourself' versus a show that dives into the shades of moral ambiguity, then Gintama is not the show for you.

That said, most of the characters are depicted in a way that the viewer could interpret as 'morally good'. I think the average person who went through what Hasegawa did - which is, constant homelessness, a complete loss of status, losing his cushy job and wife - they would, generally speaking, end up an absolute trainwreck of a person. That he goes out of his way to sacrifice job opportunities and an actual lottery jackpot (Madaodog Millionaire episode) would be highly unusual for a person at the absolute bottom of society. So that's an example of how Gintama as a whole prefers to operate - taking a character deemed 'useless' in society, only to reveal that their 'soul' is incorruptible.

Gintama also does have reverse examples, such as Oboro succumbing to jealousy after seeing Shoyou's relationship with the Joui 3 students, and Nobunobu becoming a despised leader after his ill-gained power post-SA arc. They both get their comeuppance after a while, for what it's worth.

But Hosen is admittedly egregious. He is definitely an abusive character who essentially crippled his favorite 'courtesan' simply because she had the desire to be a mother, and acted upon it. He imprisoned her and did everything in his power to subjugate her, and in a way, I think he was trying to break her. Rather than simply killing her off at her own request, which was the usual punishment for courtesans who tried to run away from Yoshiwara, he basically paraded her around to show the other courtesans what would happen if they tried to replicate what she did.

(I also do think he most likely raped and sexually abused her. I think the subtext is there because Kamui openly mocks Hosen's hyperfixation with Hinowa, who surely must have been different from the other courtesans with a 'dead' expression, catching the Yato's eye. In Yoshiwara, I don't think there is any morality or protection from that kind of deviant behavior.)

Having been in the fandom for more than a decade, I've often encountered this sort of accusation, where people are like, "She just forgave Hosen on his deathbed? That's absolutely ridiculous." There are people who think that forgiving their abuser glosses over the committed crime, or that it's holding women to an unrealistic standard.

Which I think, if you apply to the real world, is a perfectly reasonable thing to think. If someone has wronged you, it is logical to hold onto that and to wish harm on the opposing party.

But if I think about the parameters of Gintama, it seems more that Hinowa's reaction was very much in character and thematically aligned to the story that Sorachi wanted to tell. Why?

First off, Hosen died.

I think for most people, they would be relieved if the person who abused/assaulted/crippled them was going to die in front of them. Hinowa found her "karma" to work for her in the end. She saw her closure in his demise, and so I think that had to be extremely satisfying to her. I think to forgive a person who ends up living a long life despite their sins has to be exponentially more difficult than someone who 1. is going to die prematurely before their time and 2. knows he's going to Hell.

But to propose that she should have reveled in his destruction wasn't in her nature. Thematically, she was the "Sun of Yoshiwara", seen by everyone as a goddess and set above a mortal. And she demonstrated that continually in the story. She tells a young Tsukuyo that no matter the circumstances, you have to be your own person with your own dignity, and to make the best out of your own 'cage'. She is mentally tough, intelligent, and kind. In the series, she is admired by the women around her because she could rise above the mental prison and enslavement of being a courtesan, trapped in the eternal darkness of the red light district. People such as Tsukuyo looked up to her and strove towards that ideal.

If she descended into bitterness, that would debase her characterization and she would have turned into an ordinary courtesan. It would have been out of character for her and I think it would have been kind of pointless for Sorachi to paint her as this motherly, self-sacrificial person willing to do anything to raise a kid that's not even hers. I do understand that this character archetype will not appeal to the fans who prefer the "grrrr man-hating female badass babe" prototype, but I'm also like, "Well, there are so many other characters in Gintama like this," and making Hinowa into that kind of character (who's already not a warrior) would be fairly redundant and contrarian to the story that Sorachi was trying to tell.

Secondly, she lets go of her suffering when so many other characters can't, or refuses to.

As someone who personally also went through a lot of trauma and abuse in my early life, it is fucking exhausting to hold onto that amount of bitterness and exhaustion. I think if I had the ability to forgive and let go of what happened, it would be one hundred times easier for me to move through life.

There are many characters in Gintama who continually torture themselves because they are unable to forget and to forgive. Takasugi is a great example of this, who often reveals his suicidal ideation in the series as he cannot forgive himself or Gintoki for what happened to Shoyou-sensei. Gintoki often drinks himself to death, is chronically depressed, and is functionally unable to move on from his own sins during the Jouishishi war. As such, Gintoki can't accept that other people hold him in high regard and to let them in. Essentially, these two men are mentally weaker than Hinowa because they are unable to move on and it takes them over ten years to reconcile the ugly truth of their past or to even talk about it. Although the two of them possess immense physical capabilities, it's their mental weaknesses that define their characterization in the end.

Hinowa, who can forgive the most heinous crimes committed against her, is incredibly strong for not allowing the abuse to ruin her life and to dictate most of her choices post Yoshiwara in Flames arc. She is not bitter or jaded after eight years of imprisonment, which to me is a sign of strength rather than weakness.

Which brings me back to the third point...

She gets her happy ending.

In the series, Hinowa regains her ability to walk (albeit with a crutch), rendering her handicap a relic of the past. She is able to raise Seita, one of her most cherished desires in her life. And from the reader can see, she doesn't work as a courtesan anymore. She is a respected member of the community who owns her own storefront in Yoshiwara and even has access to Hosen's vault which is full of gold.

Hinowa is essentially living her best life, without the baggage of her past to weigh her down. She's a sharp contrast to the rest of the Gintama crew, in my opinion.