My problem with ideology, not that I recall it too well, is that it was a fairly arbitrary way of dividing the world into 3 blocks. It had little to do with what happened earlier in the game
See, not only I have no problem with it, a
I actually liked the fact ideology had little to do with what happened earlier in the game, because:
1) It is historical. Industrial revolution is "the singularity" in that it breaks a lot of previous processes and continuities of history. State ideologies in the 20th century were
not something determined by the course of centuries and millenia, though past history nudged certain societies in certain directions. India had zero republican history before 1947 and had very collectivist cultures yet it created stable, succesful liberal democracy at the first take (well initially with very statist planned market economy but after few decades they ended up with hard liberalism). Meanwhile Greece, Italy and Germany with their hurr long ancient legacies of republics and parlisments had periods of fascism. And sure it was "arbitrary" this way, and thank God for it, because I there is no way to break endgame tedium is late game is not allowed for some chaos and disruption.
2) Regarding gameplay, I liked how it was this chaotic process which dyjamically disrupted previous super stable webs of alliances and friendships - see also the above, it is historical too. It is a fantastic method to distrupt static boredom of the endgame, by flipping diplomacy on its head and causing "diplomatic revolutions". Again, imagine how boring real history would be if in the 20th century we'd have AGAIN wars of England vs France and Italy vs Austria and Ottomans vs Austria and Bulgaria.
and there wasn't much in the way of actual interactions with the system.
It did lack active internations (the bane of civ5 diplomacy) but it did not lack impact - the ideological pressure could completely tank and paralyze empires with unhappinness, hence it was actually useful to invest in culture/tourism and various bonuses to counteract; it reforged alliances like I mentioned; and also
There were the tenets (additional social policy essentially), but even that was just an an extra - if slightly bigger - government / social policy tree.
Tenet trees were somewhat different from the social policy trees in that you had a lot of freedom in choosing which should be taken when, and they could be very powerful, offering a ton of help towards any type of victory. They worked for the endgame much better than the previous "simply ordinary social polocy trees" since their size and freedom allowed the player to pursue any victory with any ideology tree (though iirc autocracy was significantly less universal than the other two, being focised too much on the military, so there was a balance issue there)
But I think the Civ4 Corporations system is fundamentally more interesting, more dynamic, and player driven
Corporations can't replace diplomatic revolutions and diplomatic blocs, literal revolutions, world wars and cold war.
I also actually dislike corporations in that they enforce certain economic system on the entire world of civ, which again is the allure of ideology system - what if I want to try some mixture of economic nationalism or domestic capitalism or socialism and to not allow you corporations on my lawn, and yes I want the game to give me some gameplay ressons for doing this alternative style?