mostly cause you would not get the approval for such a faction anymore...
if now someone payed 500 million ( which is still a lot of cash ) - and made a proposition like that:
- zoner affiliated
- allowed ships : outcast dreadnought, any zoner cap, any freely available fighter
- ZoI: theta and practicly anywhere else
- diplomatic status: neutral to anyone
( no, thats not the AW ) - they would never get any approval. - they would get a lot of funny responses and their 500 million would be gone for good.
many of the old factions would NEVER get an approval today. - today - ppl are more looking for the most authentic NPC copies - and try to bid themselves down to use a most restriced ZoI ( the smaller the better the RP ) and the most restricted shipuse ( the smaller the better )
the last custom faction that put a lot of work into the RP were the harvesters - and they received a whole lot of critizism, too.
so i think the reason is simply that "we" as a community make it really hard for such factions.
edit: one problem is that custom factions have custom RP canons. - and even established factions have problems with the RP canon. - how hard is it for custom factions then to have an approved canon that everyone agrees on.