That's one of things that bugs me in this kind of game. There's a lot of the trappings of a feudalistic middle ages society but the characters are walking around spouting modern ideology.
Not...really? None of the "modern ideology" in the game is intrinsically implausible; the only thing I can think of is possibly the relatively less rigid gender roles, but that's easily attributable to Andraste's existence (and in fact Gaider has made this explicit comparison on several occasions).
In fact, most ideological and political stuff about Thedas isn't terribly hard to imagine. Most countries are monarchies with large landholding aristocracies; some have an unclear smattering of freeholders; republicanism is essentially invisible except for arguably Antiva's and Tevinter's collegiate aristocratic infighting. Essentially all politics are
corporate, that is to say they are conducted on the basis of group membership and group action, and they take essentially no notice of the individual. Political institutions, insofar as they exist, are easily traceable to historical ones, such as the Tevinter Senate (clear analogy with Rome, although the bicameralism connects to medieval estate concepts) and the Fereldan Landsmeet (a glorified Frankish army assembly). Justice exists, but is scattershot and easy to subvert. There are no concepts of universal sapient rights save perhaps those advanced by the Chantry, which also makes sense because the Chantry is the only organization with an interest in universality.
All of these things 'work' by medieval European analogy.
Ideologically, the only thing that stands out as totally alien is the Qun, which is predicated on a sort of "collectivism as opposed to individualism" ideological dichotomy that is very bizarre for anything before the nineteenth century. It relies on a level of state and bureaucratic control that is technologically implausible. But that hasn't been the main thrust of complaints in this thread.
It seems like a lot of people are harping on the issue of "freedom", especially "freedom for the elves" and "freedom for the mages". It might be a little basic to point out, but freedom is not a new concept. Going by some of the comments in this thread, freaking Harmodios and Aristogeiton would be anachronistic for their own time. That oppressed groups wish to secure more community rights is nothing new. And the crucial sticking point - that they are viewed as
community rights, rather than universal or individual rights - is
quintessentially appropriate for the time period. The related issue, of southern Thedas' antipathy to slavery, is also a decent representation of the difference between eastern and western Europe around 1000; where there were few slaves in the West, largely a result of religious pressure, Constantinople was a massive slave clearinghouse, trading flesh from the Rus' and viking lands to the Muslim khilafat in the south.
In fact, I would say the opposite from you. Where you view the trappings of the setting as "feudalistic" (ugh), I view the setting's trappings as decidedly more modern. The entire Orlesian aesthetic, for instance, is basically seventeenth-century Versailles run amok. A lot of
Inquisition's clothing and armor look similarly anachronistic. The ultra-monetized economy is a late nineteenth century artifact, decidedly unmedieval. Then again, some aspects of the setting look "medieval Europe" when they really oughtn't based on other elements of the setting (fortress design is probably my biggest complaint).
I don't think it's an exaggeration to say that I'm kind of the obnoxious queen of historical analogy and plausibility on the BioWare forum, but even I would have to say that ideologically there is very little to scoff at in
Dragon Age's southern kingdoms.