Perhaps, but that describes a situation, not necessarily its cause.
People may want to be grouped with people like them, but it may be a reflection of social and economic necessity. Bit difficult to group with Old Etonians if you can’t afford the bus fare from Newham.
I take your point that you can’t make people who don’t want to wargame, wargame.
But ensuring people get opportunities to know enough about it, and letting then know that it need not all be based on European dynastic, colonial or nation state conflicts might help. Add in a bit of reasurance that it isn’t about reliving or rebranding anyone’s cultural or military hegemony might be a bonus too.
Fun, intellectual curiosity and art – all good places to start?