Art has fallen into the same sort of trap as architecture, where you get otherwise-intelligent, otherwise-tasteful students of the field -- like the author of McMansion Hell -- swooning over abominations like Boston's Government Center. Trust your heart, not academia. Refine your heart, to be sure (art is that which doesn't fall apart when you start asking questions about it); but trust it.
But in terms of advancing games as an art form, I think aesthetics that are more "grammatical" and "open" is the way forward (think comics/animation, Studio Ghibli). This doesn't eschew the use of Realism, but changes it from being the pinnacle we're striving for to a tool (among others) to be used in creating better art.
I think that's why those type of paintings are considered old-fashioned and silly when we have plenty of photographs, movies, and books that tell us what these regions are actually like. Not to mention that travel is now far more accessible to non-wealthy people.
I think that it's a fascinating insight into Europe at the time and how they viewed the world. It was also a lot more romantic period than now. Nationalistic paintings showing a nation's ancestors (like the Germanic tribes of the Roman era) were popular and tended to look the same way: a fantasy land ideal of what they wanted it to look like rather than what it really looked like.