When considering ideologies, I don't even stop to think about Autocracy. The benefits currently aren't worth the happiness hits + tourism penalties. I've noticed no AI has come close to winning a conquest victory in any of my games - this might explain their hesitancy to pick Autocracy. Why devote your culture to an ideology which specializes in something that has nothing to do with the way you're playing your game?
Happiness hit? That'll happen with ANY ideology if your culture is weak. Autocracy has some of the best ways to REVERSE the happiness hit from a weak culture, and if you are the strong culture, you become the happiest, safest population on the planet. Futurism can help increase your influence bit by bit, Militarism has the double effect of giving you a very cheap way to get +6 happiness in every city and making your new army units stronger, fortified borders stacks with Neuschwanstein to make Castles incredible, and Prora is unmatched in pure happiness output, and gets better as the game goes on longer.
Autocracy isn't ONLY good at conquest, although it is by far the best AT conquest, it's just that all its avenues for victory synergize well with having a huge army. Why do people keep saying that Autocracy is bad at culture victory when it has the only Tier 1 that even AFFECTS Tourism? Freedom has to wait till Tier 3 to affect Tourism at all, and Order only affects tourism on a narrow band -- yes, it's an easy band to hit because most AIs pick Order, but that one Freedom civ will dash your dreams of culture victory, as they are most likely be the happiest population and a high culture output, making them impervious to Order. Yes, Freedom and Order can increase tourism passively, but Autocracy has access to both the largest tourism boosting factor in the game, and the only factor which stacks with itself.
If Futurism were any better, Autocracy would be the go-to for culture victory. Cult of Personality gets panned so much, but you don't have to start the wars and make a written agreement for a joint war to happen. The AI is always declaring war on each other, and you can get Cult of Personality to work just by declaring afterwards, and as long as you don't conquer any cities, you don't get a very large warmonger penalty. You can scare the AI into giving you all their things to stop your tanks, and if you didn't conquer, they might not even hold a grudge. If there's a stubborn culture that refuses to join you, declare war on that culture's enemies (he has plenty), and for each enemy you declare with, you get a
stacking +50% increase to tourism to that civ.
At one point, I was pumping out a whopping +1500 Tourism to certain other civs
per turn through Cult of Personality. I wasn't the mighty conqueror, I was the benevolent Sword of Justice, keeping the REAL warmongers in check, while wowing everyone with my gorgeous resorts and museums filled with artifacts of our rich history of warfare. The city-states loved me because I had been saving them from barbarians and assisting in wars against other civs, liberating them when needed, and such was my might that the mere presence of my elite forces would sway their opinions. Such was my production that I doubled the second best at the World Games. I even rescued Mongolia from the evil clutches of their Austrian oppressors. I wasn't even attempting a Domination victory -- I had both culture AND diplomatic victory in the bag. I was the first to adopt Autocracy, and was the only surviving civ to do so. Yes, I had happiness problems in the beginning, but by the end, I had the happiest population on the planet.
While it is true that the AI is usually hesitant to pick Autocracy because they'd rather win a science victory, there is one civ out there who picks Autocracy EVERY time, and he is very dangerous: Greece. Alexander almost always becomes a runaway if left to his own devices, and he only stops Dominating because he realizes he can win Diplomatically, and he WILL win diplomatically if he becomes a runaway. He never picks Order because he prefers the diplomatic victory, and he never picks freedom because war is his drug of choice.
Autocracy is a very unique, and in my opinion, VERY fun style of play, where you use the might of your armies to leverage every other thing you do. Once you have the best army, Gunboat Diplomacy can turn allies in no time at all with just 3 of your battleships parked outside each of their borders, letting you save gold to spend on either more units, or on improvements, and Cult of Personality gives you a massive Tourism boost whenever you jump in on someone else's war, which also gives you major props with those AIs if you save them from a powerful enemy and don't conquer any cities yourself.