You can count me a card carrying member of the Akira GitS Cult.
And I think Ninja Scroll did so well because it filled a void that was left behind by Fist of the North Star. It was a violently over the top animated movie. And there was a market for that. After all, there was a certain novelty to "Violent Cartoons" back in the early 90's. Which was coming off the era of GI Joe and 5 minute long gun battles where nobody ever hit anything with a gun ever. I think the only character to ever be shot and killed(later put into a coma) was duke... and he was shot by a god damn snake.
So yeah. The scene in the beginning of Akira, where the revolutionary is gunned down by like 15 gunmen, seemed to almost poke fun at western animation. (See! When we have 15 guys shoot at someone they hit their target.) Conversely, I watched Akira in Highschool during 2 separate occasions. Both times, there was riotous applause for that scene. Not so much because a nameless schlub was gunned down. But because a ton of bullets just flew and didn't hit air. (Wow, a cartoon character just got shot to shit!) That sorta thing isn't as amazing these days. (if anything, it may turn a few viewers off) but back then, it was like finally taking the kid gloves off .
And the top sellers then where series like Violence Jack, M.D. Geist, Genocyber, Ninja Scroll, Fist of the North Star, Vampire Hunter D, and Akira. Which, with the exception of Akira and maybe Genocyber, isn't a list of stellar movies and series. Hell FotNS is probably MST3k worthy on it's own. So Utterly bad it's hilariously good. But that doesn't make these series any less important to NA fandom. These did something that Speed Racer, Gatchman, Kimba, Astro Boy, Voltron and Even Macross couldn't do. It made North America take notice of Anime.
And I'd even venture a guess that people wouldn't have even bothered to fansub some of the more popular shows coming out of Japan these days, if it wasn't for these series. They created demand for a product that western companies where having a hard time fulfilling. For every animeigo (Bringers of bubblegum crisis and Ah! My Goddess) and Viz (Ranma 1/2) there was a Streamline (Everything after Fist and Akira should have been called Shit Release #X) and USRenditions (You don't know what a bad dub is till you watch the USR Macross 2 dub).
Someone had to fill the void shitty translations and crappy dubbing left. And Fansubbers filled that void. And even though there where fansubbers before that. There just weren't many of them. Anime fandom was more akin to fans of Spanish Novella's today. Just a type of show in a different language that you really didn't watch unless you understood the language. Maybe you had a friend that got you into it when they subtitled it for you. But your friend definitely didn't have a comprehensive list of subtitled work. So fansubbers filled the void and the internet became their medium of choice. (why the hell wouldn't it be?)
TL:DR
Uber violent anime created a market and shitty localization boosted fansubbing to fill that market. So thank Ninja Scroll and U.S.Renditions for the fact that you saw any of these shows in our lists.
