I know this comment is a few months later, but I have to agree on some points. The reason why I started watching Asian dramas instead of American ones (after watching all the Jane Austen and Charles Dickens adaptations over and over) is because many of the new and popular dramas have nudity and extreme violence. Normally, some violence doesn't make me too uncomfortable (I've seen some bloody movies when I was younger), but I've found that as I get older, I've become more sensitive to that. Also, there isn't a lot of flying (if at all, unless on dragons). One thing I do appreciate is American CGI, which can be lifelike, whereas with some Asian dramas, that isn't the case. Also, at least in the dramas and movies I watched, the love triangles weren't as prominent, but then again, I tended to stay away from the popular romance movies/dramas due to nudity and sex. Another difference is storytelling. Asian dramas and American dramas tell stories differently...I have a harder time trying to point out how. I'll try and put it this way: American period dramas rely more on dialogue than actions, whereas in Asian period dramas, looks, gestures, and actions are everything. American history is also drastically different than Asian history, since many Asian countries have had dynasties, whereas America was born from a revolution.
Plus, I'd like to point out that modern American literature loves realism. A lot of the films tend to head that way as well, but there needs to be a line between realism and glorification of immorality and violence, imo.
I think American movies do incorporate some of these themes, but not as obviously. One just has to find those beautiful movies/ dramas, and they are there, just some digging is required. British dramas are pretty good about this as well.
By the way, I loved the drama Merlin--everyone was so flawed, and the legend of Arthur was well told.
Anyways, I'm done.