The realism probably has a say in it as well. Most general JRPGs and things derived from them have a more stylized medieval fantasy setting. Dark Souls its more closely related to Dungeons and Dragons. Which, I know, inspired most JRPGs as well. But they still put their own spin on it, and gave everyone big eyes or big heads or crazy hair or dresses and whatnot. Nothing realistic. Dark Souls is kind of like what life would really be like in a bleak world like that. Something things like Elder Scrolls and Fallout attempt to achieve. Western RPGs are more grounded in an attempt at realism, at least in look and aesthetic. That's where I consider Dark Souls to be more West-like at any rate. I'm sure others have their own reasons