Mixed Metaphor has, since its inception, been about the Federation, and given that we existed since 2007, we (and by we, I mean me and Faust, currently - we don't have any other active members) preceeded the newer generation of Gallente militia RP corporations by a year or so. Around 3Q/4Q 2008, just after the war with Exalted, was our corporation's high-point - after a somewhat disastrous war, we immediately bounced back by merging with Vincent Pryce's old corporation and decisively winning two wars, including one against a well-respected mercenary group. Our active membership exceeded 20 competent PvPers and we were actually a fairly big name in FW simply on the basis of two of our Finnish members who were going around in a Thorax/Blackbird twosome and raping things (it was also when Vincent began his meteoric rise to PvP Monster Under The Bed by suiciding ALLAH AKBAR JIHAAAAAAAAAAAAAAAAAAAAAAAAAAAAAADing his Blackbird against a Hyperion so we could kill it). After the corporation kind of fell apart due to the unpleasantness involving CHINX alliance (yes, that was their actual ticker).
We've never been able to recoup our numbers because it's an extremely hard sell to make a Gallente RP corporation. Evanda Char commiserated with me when I complained to her about it that, yes, indeed, it's difficult, because Amarr and Minmatar have a very clear, uncomplicated face for their roleplay which you can dive straight into without having to consider very much:
Amarr - Theocratic despotism. Keeps slaves. They're the Bad Guys, and it's often fun to play the bad guys!
Minmatar - Plucky underdogs with a MacGuyver approach both to technology and to everyday life. Oppressed and kept as slaves for generations. They're the Good Guys, and it's often fun to play the good guys!
You can get into RP based solely on these principles. You don't ever have to go any further. But neither side is as simple as these basics. When you look into them, there's a lot of nuance to either side if you want to delve that deep:
Amarr - Not always the Bad Guys. Some despise slavery, some despise the system of government and some are inspired by their religion to do wonderful, selfless things. Even if it's for all the wrong reasons, the Amarr are occasionally a source of good in New Eden.
Minmatar - Not always the Good Guys. Sure, they were oppressed, but some just use that as an excuse for violence and savagery. The quality of life in their empire is pretty low for the average citizen and people are flocking to their more comfortable neighbour, the Federation, to get away from it all. The Republic's fringe is just as rife with extremists and barbarians as the Empire's.
What's good about the Amarr/Minmatar roleplay scene, and what's kept it so healthy for eight years or more, is that it has a very clear face value Good/Evil divide which ropes players in, but enough nuance and moral grey underneath it to keep serious roleplayers interested.
The Gallente/Caldari are way, way more complex than that, both underneath the surface, which is good, and at face value, which isn't. There is no clear face-value Good/Evil divide with the Gallente-Caldari, and that definitely hurts. What the Gallente-Caldari have are societies that are fundamentally almost identical, feuding over a series of complex, nuanced nationalistic and ideological differences. While this would be great as the basis for a series of sci-fi novels, it's a much, much harder proposal to sell to players in an MMO, making their characters, who want simple concepts now to base more complex ideas on later.
Liberal democracy vs. corporate plutocracy (or mob rule vs. meritocracy) is way harder to sell than freedom vs. slavery (or terrorism vs. rule of law). Mixed Metaphor's old core membership were either roleplayers who were genuinely interested in playing defenders of democracy, or non-RPing PvPers interested in the constant trouble my mouth and my character's mouth got us into. We didn't really get anyone else, and it's hard to recruit roleplayers for the Federation right now.