I greatly appreciate that CCP has apparently decided to do away with our proto-Space Hitler. While I thought that the notion of a Caldari fascist demagogue was actually pretty believable (they really do kind of walk the fine line re: fascism), this is a good "The Caldari are not the goddamn Helghast" moment.
I can see where you're coming from, but I always felt that the Caldari (for all the elements that are homogeneous) are pretty fractured as a society. That's one of the reasons the base idea didn't seem incredibly likely to me (leaving aside issues of execution of his rise).
The State's tendency towards factionalism is subject to a couple factors that took turns poking their noses out in the Heth storyline.
(1) The Caldari culture transcends megacorporate identity, meaning that a leader whose support arises from said cultural underpinnings can unite workers of many corporations. See, e.g., the Brothers of Freedom incident. This was Heth's power base-- the working class, not the State factions.
(2) "Me against my brother; me and my brother against my uncle; me, my brother, and my uncle against the stranger." However much they bicker amongst themselves, the Caldari pull together against an outside enemy. The Malkalen incident and subsequent provocations on Caldari Prime renewed the old anger against the Gallente, and Tibus Heth stoked the fires of nationalism high.
This whole thing was an exception to State factionalism that might have eliminated the State factions and united the Caldari if Heth had immediately made that unity his top priority. If that had occurred, the Caldari would likely have become properly fascist.
It didn't. They aren't. The Templis Dragonaurs are probably going to have to wait another two or three generations before they even might get another crack at power unless the corporate factions are amazingly stupid, but that doesn't mean that the Caldari are too fractious ever to become fascist-- only that the Dragonaur-in-chief bungled the job.