I think the issue is more what the writer either subconsciously or consciously associates with their setting, not necessarily what would be the most interesting, reasonable, original character, however unlikely. Loads of great fictional characters are unlikely, that should go without saying.
For example, let's switch this around. I'm English. Let's say I dream up a historical-ish, fantasy-ish story about cowboys and monsters in the mid-west. My main influences for this aren't data, or any interest in actual American history. They are westerns. My story takes as it's influence the cowboy programmes and films I watched with my dad, already filtered through both my childhood memories and those of US TV writers fifty-odd years ago. It would probably contain bits of True Grit, The Good, the Bad and the Ugly, High Noon, Bonanza, the Magnificent Seven, etc etc etc. As much as I might knuckle down and do the research, in reality what I want to make is a fiction based on fictional stereotypes, rather than one based on reality. If all my influences are square-jawed white guys, as a hack the laziest option is that I want Clint Eastwood as the lead.
That's a minor problem with games being stuck in genre fiction, we're retelling childhood dreams of heroes and villains, monsters, cowboys, detectives, knights, space soldiers and dragons, just as writers fifty years ago were doing. But the main problem is poor writers and why I shouldn't be one.