It's just more a matter of player demographics Arkon. Most minmatar RPers play outsiders and anti republicans. Some have reconciled a bit with Shakor new government, but at the same time Gradient and EM were the only real bastions of republic loyalists, and well, you know what happened.
So, there is a void for republic loyalists, and since it often interests a lot less the players usually...
Take it like the Caldari for example : half play Ishukone, if not more, and the rest play patriots like KK or just patriots. Also, Dragonaurs. But practicals ? Those are a rare breed, a lot more than in the past, which was already barely a few individuals. Same for Kador ? Who the hell play a kadorite ? It's either Sarum or Kor-Azor most of the time. TM and Ardishapur are just a few ones that stray from the mainstream. The only very diverse ones are the gallente, albeit I can argue that I have yet to see a sociocrat (2nd most powerful party in the fed with the liberals), which is a shame because that party is heavily associated with Mentas Blaque, who is painted an opportunistic villain with nothing of a sociocrat.
So yes, there is particular subfactions that are rarely, if not, played. And the Republic side of the Minmatar can at times be one of them, and that's an issue because the Republic is the most important of all of them for the Minmatar (their government !).