It's not corruption. He has stated that there were projects going on behind the scenes, but most of them got scrapped before reaching production.
The most recent manga he involved with was Ghost Urn, which explores the world of GitS from a different protagonist. He did not do the drawing, but did most of the worldbuilding and mecha design.
He's always been a very horny creator and the original Ghost In the Shell movie (in fairness not directed by him) has the female main character need to get nude to use her stealth ability while the men can leave their clothes on.
Whatever narrative you've invented of Shirow changing over time is a stretch.
If you've seen the original movie, other than nudity there is very little horny in it. No sex, no banter about sex, no erotica. The female body, even if well endowed, is depicted clinically and emotionless. There are no lecherous characters, nobody chasing girls, etc. No romance even, though the relationship between Motoko and Batou is somewhat ambiguous.
Shirow's manga is horny though, partly why I dislike it.
I think the sexuality of Kusanagi works on multiple levels. She is a full cyborg, and she could present however she wishes. She explicitly uses her appearance toward social engineering ends in the Stand Alone Complex series. I’m not very familiar with the manga, from what I do remember, Kusanagi is bisexual and is likely “fully functional” sexually, but her body as depicted isn’t really her own, as she relies upon regular maintenance provided Section 9.
I view the portrayal of Kusanagi as being steeped in aspects of the male gaze in a metatextual way. Japanese society has a high emphasis on traditional beauty standards, and the artists depicting her as a character use her beauty as a foil against the audience, by contrasting her beauty with her strength, and by subverting the desires of the audience by drawing our attention to her humanity by alienation through destroying her body at multiple points in the series. Her desire to protect her comrades at the cost of her body shows us how she is willing to sacrifice her femininity, being forced to regress to a childlike body.
The series have a lot of fan service, but I believe that it’s intentional so that the audience is forced to confront their own biases and stereotypes about women and about cyborgs/robots. The cyborg nature of her body as it is destroyed reads to me as a visual metaphor for the Madonna/whore double standard women are subject to society.
I guess I don’t disagree with your view, so much as I think that how she is depicted works on multiple levels in-universe and with respect to the viewer, and said depictions serve multiple functions in the text.
In the movie Kusanagi isn't bisexual. No reference is made to her sexuality at all. One could argue her demeanor is completely asexual. The only human side we see of her is her wondering whether she's human at all.
Movie Kusanagi is her own thing, mostly unrelated to the manga or other adaptations.
Yes, I addressed this: Kusanagi appears naked often; the intro scene is definitely striking and somewhat of fan service. However, there's little sexy about this in the movie, the characters don't behave sexy, there are no lecherous moments, etc. In fact, sex is barely acknowledged at all. It's not a "horny" movie.
A lot of mangaka have done that sort of thing, calling something normal in the industry "infamous" and "corrupting" seems overblown when Tatsuya Matsuki and Nobuhiro Watsuki are grooming children and collecting CP and every other mangaka seems to be shitposting racism.
I called it infamous not because I have a particular problem with it, but because of the way it's characterized by (Western, at least) fans. They snicker at and make jokes about the scenarios he apparently employs. (Admittedly, it doesn't sound like my thing, and I haven't looked too deeply into the material. It could very well be that I'm getting trolled.)
I agree that you can find genuinely disturbing things in the manga world and that Masamune's work is relatively benign (though some of his depictions of less-developed adult women might upset some). In general, I find the idea of commercialized erotica amusing, especially when coming from sources with more mainstream claims-to-fame. In these cases, I don't attach a connotation of moral bankruptcy or anything like that to the idea of them being "infamous", though maybe that's just me using the word wrong. I intend it more in the sense of, "Hahah, oh wow, THAT guy did THAT? That's crazy." Kind of like when we found out about Tezuka's softcore furry/snakewomen doodles.
The most recent manga he involved with was Ghost Urn, which explores the world of GitS from a different protagonist. He did not do the drawing, but did most of the worldbuilding and mecha design.