"Civ V" lets you build a civilization (of humans) "to stand the test of time." In game terms, this means you start with stone-age settlers and end up with world domination, in or before the modern age.
That's the first thing that's horrifying in hindsight, to someone who grew up with these games and just played them again last night. The goal isn't to coexist and appreciate global diversity. It's to dominate all life on Earth, whether through armed conflict or cultural hegemony. And while there are benefits to cooperating with "minor city-states," in your struggle against the other players, by the modern age you drop all pretense of a mutually beneficial relationship and go straight to rigging elections. Because if you don't, your opponents' spies will.
The second thing is the cultural biases. They let you choose from dozens of historical leaders, but whether you're playing Boudica, Hiawatha, or George Washington you end up playing America F*** Yeah in practice. Either that, or a cartoon version of 20th century dictatorships.
Here's a short list of disturbing stuff from the "social policies" interface, as of the Gods and Kings expansion (I'm one behind):
"Faith" and "Rationalism" are mutually exclusive.
Socialism is a precursor to Communism in the "Order" policy tree. You can't have it active at the same time as "Liberty," which is the only way to grant universal suffrage.
Somehow, you can have Theocracy and Religious Tolerance active at the same time (and are rewarded for doing so).
There is an honest-to-goddess Meritocracy social policy, which was not ironically named (at least not on purpose).
You're rewarded for producing Great Artists, Engineers, Scientists, and so on, all of whom are named after real-world figures. There's no argument or discussion about what makes these people "great," and there are an awful lot of white guys, like patent troll Orville Wright.
Building a bank and stock exchange in every city won't result in rampant speculation, housing crises, and market crashes. There's no such thing as international banking. Money's a tool to be used by political leaders.
"Wonders of the World" are unique and exclusive, to the point where if your civilization's one turn behind in producing the Sistine Chapel you have to abandon it and start over once Catherine of Russia builds it instead. Awe-inspiring temples and monuments aren't ways to bring the world together, they're just more tools for domination and promoting inequality.
"Natural Wonders" are special and inviolate, and can't be "improved" by your Workers. They're pretty much the only land tiles that are like this, however. Everything, and I mean everything else, eventually gets railroad tracks, lumber mills, and strip mines laid out across it, until your country's a patchwork of farms, city skylines, and smokestacks. There are no ecological consequences to building coal-fired factories, nuclear power plants, dams, quarries, and gaudy landmarks everywhere. The sea level does not rise. Resources are never depleted. No continent-sized islands of garbage form in the ocean. If nonhuman species go extinct, you don't hear about them.
And that, to me, is the most horrifying thing about Civ V. Watching a game of it play out feels, to me, like it might to most humans watching the robots from the Matrix plate the Earth in cast iron. Nonhuman species have zero agency, zero voice, and zero way to fight back as they are annihilated, mere obstacles in the way of "progress." Rewards for leaving wild areas wild are few and far between, and there's always the possibility that you'll strike oil right next to the Great Barrier Reef.
This game is nightmarish.
I'll stop playing after I finish one more turn. :P