I am also one of the few Jupiter fans.
Also, I think what would make both the "singing girl" fanboys happy and the Jupiter fangirls happy is if they made a spinoff "girls side" of iDOLM@STER with Jupiter, Ryo as the resident shota trap, and a few new male idols, and call it "THE iDOLM@STER: Girls' Side" or something like that, like they do with Tokimeki Memorial or Da Capo. Unlike Da Capo, iDOLM@STER has a considerable female fanbase as it is, so I could see this working.
Jupiter get their own game with other bishies and shotas, the fangirls are happy they get their own game and are able to be produced, the fanboys (and girly girls, as I have a female friend who doesn't like Jupiter because she finds female characters easier to relate to) are happy that they aren't stinking up their all girls iDOLM@STER.