[lhnz]

You can't get the max diversity of ideas while only pulling people from a small number of cultures, however cultures and viewpoints aren't merely an effect of race and so you also cannot achieve diversity of ideas by just diversifying race.

This is all smoke-and-mirrors though. In 2017 when people argue for or against idea diversity, they're almost always just fighting a trojan war for or against redistribution of resources from 'privileged' to 'oppressed' (or if you're right-wing: from 'deserving' to 'undeserving'.)