This is the fundamental difference between historical fiction and fiction written in a historical period. No matter how hard we try, we can never really capture the same feel or attitudes of writers like Austen, Dickens, and Walter Scott because we aren't products of their time periods, and we don't know what to take for granted.
When PBS was running its House series, this was an ongoing issue. Interestingly enough, the best of the series (1940s and Manor House) insisted that the participants follow certain rules. The participants weren't just stuck in a time period and expected to enjoy/endure it. They had to agree to comply with appropriate social protocols (the servants had to behave as and do the work of servants; the WWII family had to endure air-raids and suffer food privations).
I think writers of historical fiction can capture the tone and feel of a time period's mindset. I think they can even give us insights into that mindset. I also think it can never be a perfect fit. I am currently working on a "between the lines" telling of Pamela (with literary commentary). At one point, I entertained the possibility that my hero would make a dismissive statement about politicians (whom he doesn't care for) by referring to Wilberforce and "those yapping members" who won't shut up about slavery.
I couldn't do it, partly because actually my hero wouldn't care about slavery one way or the other (none of his money is invested in the West Indies), partly because his wife would likely support Wilberforce, but mostly because from a modern 21st century point of view, such an attitude makes him an awful human being. I could argue that as a product of his culture, the hero would have perceived Wilberforce and his supporters (whom I admire) as simply one cause/voice/idea amongst many, but that knowledge doesn't leap the empathy gap.
(Black Adder was brave enough to tackle this idea. In Black Adder the Third, when Baldrick runs for Parliament, this conversation ensues between a fellow politician and a (real) television journalist:
Ivor Biggun: We're for the compulsory serving of asparagus at breakfast, free corsets for the under-5s and the abolition of slavery.Still, historical fiction can never completely mesh with the mindset of a historical time period, no matter how brave the writer.
Vincent Hanna, His Own Great Great Great Grandfather: I'm sure many moderate people would respect your stand on asparagus, but what about all this extremist nonsense about abolishing slavery?
Ivor Biggun: Oh, that! We just put that in for a joke! See you next year!)
Which doesn't mean it shouldn't try.
I think every reader has a tipping point, a point where the non-historical mindset becomes too much--the story isn't history anymore; it's just modernism dressed up in historical clothes. The tipping point is different for everyone. I am quite ready to accept non-accuracies in books when the writers don't pretend they are doing anything else but having fun. I despise non-accuracies where the good characters are good ONLY because they reflect modern ways of thinking.
So I quite like Ellis Peters' Cadfael series because although Cadfael is a trifle progressive for his time period, Peters never fails to bring him back to a core reality. And she only allows him to be progressive over issues that were raised in that time period. And, as a monk, he is a true believer. (Peters knew how to write 1960's "all spirituality is relative" stuff; she didn't do it with Cadfael because it wouldn't have been accurate, and she was a reputable historian.)
In comparison, I get mighty tired of books where women become suffragettes/pro-women's rights/pro-contemporary-progressive-issues without having to suffer any of the actual consequences of the time period and/or without understanding their choices from within the mindset of the time period. (This type of characterization can be done; it's just very difficult.) I couldn't stand The Red Tent because the women were so hopelessly modern and the men so hopelessly not. Geez, people, if you're going to play this game, play it fair.
On the other hand, Amelia Peabody in Elizabeth Peters' Egypt series is a good example of a "modern" woman who, at least in the first few books (I haven't read more), doesn't stray too far in her opinions out of what was actually likely for a woman to think in the late nineteenth century (the nineteenth century produced some very interesting and independent women).
Back to books I get tired of: those which simply transfer modern arguments to historical settings. I gave up on one author when she had a conversation, taking place in approximately 100 C.E., sound like a conversation between a modern-day "free thinker" and modern-day fundamentalist. (She also had the characters using and referring to the Christian Cross as if it meant the same thing to them as it does to us in the same way, i.e. 1500+ years of Christian iconography. Um, no.)
On the other hand, I quite like Deanna Raybourn's Lady Julia series. She may take a few liberties (it's not my time period, so I'm not sure), but the attitudes are consistent and don't take sudden leaps into implausibility. I feel the same way about C.S. Harris' Sebastian St. Cyr mysteries (although the PLOT of the romance in those mysteries is a bit too deux ex machina: everyone conveniently isn't available when he or she shouldn't be available).
In any case, the "oh, that doesn't work!" wince is different for everyone. It may depend on what history you've have read; it may just depend on what feels right at the gut level. But it's there. As long as there is historical fiction (may it continue forever), it won't ever go away.