I think that's the issue. The Minmatar in themselves do not really lack of interest as a faction, especially flavour wise. They have a lot of strong pros playing in their favour as Miz pointed.
The issue is the Republic. Supporting the Republic, is similar to supporting CONCORD or the Mandate. It's like shooting oneself in the foot. Not that it's completely uninteresting imo, but be ready to spend your time admitting to everyone arguing with you "Yeah, we suck... I try to do something to improve things, no matter how stupid and incompetent my faction is, I am still loyal, for what it's worth".
Since well, basically, you have near to zero arguments that can work in your favour, so the only remaining thing to do is to admit that it's a lost cause.
That being said, now that the fail Midular republic has fallen, and replaced by the Shakor tribal council thingy, isn't there a bit of room for improvement ? Things seem to be depicted as improving on that side for the Matari, even with all the issues they have besides... There might be stuff to build around the Tribal lore and caravans they added in the last news on the matter.