There've been a number of shoujo manga with similar premises (reverse harem and magic academy) before then that never got a big break or even got known for it. It's already straining my SoD that this got approved for an anime (well, unless it was a slow season). Also, Negima's main draw was first building up on Love Hina's rep and then doing a surprising bait and switch to shounen. Not a formula that would work with the audience that would watch a reverse harem anime at this time period.
Eh, sorry, but like I mentioned in my previous comments about Iron Combatant, it doesn't have the elements that would make it popular with the mecha crowd in Japan. Ballistic Limit would have a better chance, but it still has to go against the Japanese stereotype of Western games being kusoge. It's a rep that's mostly due to most Japanese publishers being too lazy to do proper translation and localization of Western stuff (or not even bothering to remove known bugs and glitches in the pre-GC/PS2 days). It didn't even really stop until 2010 and beyond (there's a reason why we're only now seeing stuff like Arkham Knight more easily break and stay in the top 20 on the Japanese weekly sales charts where pre-2010, everyone just goes "is that thing coated in crack cocaine?" when a Western game even gets into the list). Every time I go to see a Let's Play in Nico Nico or some other Japanese site for a "localized" (and I use that term derisively) Western game from before 2010 I grit my teeth at the large numbers of dry translations, control prompts and stage objectives that aren't translated, and outright missing information in story and dialogue. Let's look at Eternal Darkness as an example of a good pre-2010 Japanese localization. You can say it's Western due to it being mostly done by Silicon Knights, but since Nintendo's the publisher, it should be a solid localization, right? Well, it's OK, but no dubs, the subtitles are bare bones and don't quite match the dialogue at certain points. Now imagine worse going on for years on end and you get a Japanese audience whose instinctual reaction to Western games is "Oh, it's shit." Being lazy ass localizers was a deep-seated problem in Japan's video game industry that no one really talked about in the West. You guys needed to have some huge event in one of your previous posts dealing with that back in the early days of the SNES-CD to make me believe that the Japanese bias against Western games was being dealt with enough that these games were having great cultural influences on manga and anime.
Not Japanese, but I did spend a lot of time there in my youth as well as working there for some time in my adulthood, so I had a pretty good view of the trends back then (as well as why I get pissy at the Japanese localization efforts of that time).