Finally, the other dimension of diversity I would mention is ideological, philosophical, and religious—and this has worked in an odd way for me. I’m aware that a lot of gamers come from a military background and tend to lean conservative. (I myself am not conservative, nor do I have any military background.) However, my circle in San Diego were predominantly progressive, and the core members almost exclusively so; the ideological spectrum ranged from a couple of moderate Republicans (who are now never-Trumpers or outright Democrats) to liberal to bitterly intolerant liberal. This meant that there was a sort of “diversity” here, in that my players were sitting down with me, and I’m a fairly hard core libertarian. The only one who’s close to me ideologically is C (perhaps not surprising, as she and I are married!).
In general, this doesn’t come up during games, though occasionally after-game conversations veer into ideology. But more importantly, I don’t use my game worlds as vehicles for preaching any particular ideology. My goal isn’t to run a utopia (a “good” world) or dystopia (an “evil” world—not merely a bad one in a neutral, factual way, but one where harmful things are actively imposed out of moral conviction), but often to run a heterotopia (a different and interesting world). My point of view does suggest questions to ask about a world, and tools to use in answering them. But the explicit beliefs of characters in a world may be quite different from my own; they have to make sense in their own terms, and not as mouthpieces for GM sermons.
There’s less of an incompatibility on religious matters; I think my players have largely tended to agnostic or atheistic. I have had the odd pagan, including one woman who became a practicing shaman; in one campaign I had a devout evangelical (my one East Asian player, by the way); and I’ve had some players who would consider themselves spiritual. Now I was introduced to gaming by people most of whom were seriously Christian in one denomination or another, but that was long in the past. And we secularists haven’t been inclined to argue with the pagans, or vice versa.
(I should note that one of C’s and my closer friends, the woman who officiated at our wedding, is an evangelical literalist. But she’s not a gamer.)