IMO, both
@Arent11 and
@Krikkit1 are entirely correct here, but they're looking at different sides of the same coin.
The "issue" is that what Culture is
used for in Civilization is related to socio-political ideas, but the way it's
generated is via art (mostly). The word "culture" in everyday speech does cover both of these facets, but they are still very different things. While they do sometimes overlap (such as in propaganda), not many people would call a treatise like
On The Wealth of Nations a work of art, just like few people would claim that Bach's music inspired social change across Europe. But in Civilization these two very different meanings of culture are fused together and that's where the weirdness happens: like Picasso making a city change which empire it belongs to, or building an Opera in order to get professional armies sooner.
Of course this is just one example of what Civ does everywhere; it takes inspiration from a broad historical phenomenon, abstracts it away into a gameplay element, and digs through history to find names for techs / civics / units / buildings / whatever. Of course things look absurd and ahistorical when you look too closely at this abstraction, especially because the flavour and the mechanics are inspired by different aspects of the same underlying historical thing. There might be a lesson here we could apply to some of the more contentious aspects of CIv7...