So it is less of a subject thing and more of a level playing field. People wont mind if it was presidents or famous singers, actors etc. But a local weatherman for instance, how would the rest of the world know.
This goes for every country btw DaVinci is a fair question, but the local butcher in the same city wouldnt be, because the rest of the world wont know about it.
Though admittedly there is also a portion that doés complain about the subject matter (like on a writers quiz where most answers are american). But I would say just disregard those people. If the balance is right. So no american answers non american have no chance of knowing, and inclusion of non american answers with the same rule; that there is a chance of people outside that country to know the answer. There might be great Moldovian or East-Timorese writers, but not many world reknown ones).