Not comparable, since in your case its a matter of livelihood.
This goes beyond Reimu and Smash, this is a thing that permeates pop culture people in general. It's the same vein as "Read another book that isn't Harry Potter," or "Watch a movie that isn't MCU"
This whole "It's Japanese? Must be weird/obscure" thing is everywhere and it never gets any less infuriating because it is almost exclusively an American thing. It's why we get things like DmC before DMC5. It's why we get things like JelloApocalypse's stupid Pizza Game.
Hell, going back to Smash, look at how people reacted to Terry in the states. Unless they're huge into the FGC, they mostly reacted with "Who?"
Go back to E3 with Hero and Joker's reveal. "What's Dragon Quest? Popular in Japan? Who cares lol"
Because like, God forbid, that countries outside of America have thriving communities for a specific game that didn't reach stateside. Like, hell
"This game is about a Japanese man, who is a retired career criminal trying to find the father of his adoptive daughter's child? It's a weird game made by the weirdly racist Japanese. But God of War 2018? Masterpiece title. AAA+ game that is perfect for us who want real mature stories."
Like, the fact that Yakuza 0 got popular and revived the series in the west because of a chicken in a side-quest is a perfect representation of my issues. It wasn't because "Wow, this game is shockingly heartfelt, I wasn't expecting this out of a game that is about the Japanese mafia," it was because "Oh wow, this game lets me put a chicken as a real estate manager! Ah, those crazy Japanese and their funny ideas!"
Do you not see the issue here?
Is it an issue? Sure. Does it constitute basically telling a teenager they're dumb for not knowing something? Absolutely not. You're not winning anybody over, or going to convince somebody to appreciate the things you appreciate by saying, "You're not smart for not knowing this stuff."
When it comes to games like Yakuza and God of War, they're both series that have different histories to them as well. God of War far and away has had more attraction to Western audiences. I wouldn't really say it's a racism thing, but more something related to the legacy and branding of particular series. God of War is also an exclusive to one of the big 3 console makers, that certainly helps the marketing of it to the western gaming fanbase.
That quote you used to describe Yakuza and God of War is certainly not characteristic of an entire body of consumers, and I think it's not supportive of your point when you say that people "judge" a game based on appearances, when you yourself are judging people because they might not play the games you like. I also don't think it's out of the question that...maybe God of War and Yakuza are both great games?
It comes down to culture, but also business decisions and marketing. Mario, Zelda, and other games do well everywhere because of how they are perceived. Based on culture in the west, I personally, wouldn't really see Touhou making it mainstream. It's a game with several characters being young Japanese girls, when the market is mainly driven by games in which you shoot other people. That's a pretty tough sell.
I agree that people should be more open to new things, as that's half the reason I love Smash and the games involved. I just think there'd need to be far more moving parts for more folks in the west to be more open to games like Touhou, whether it's based on gameplay, or aesthetic. i understand your frustration though, I'm sure that gets old.
Alas, my point is this: You get more bees with honey than vinegar. If you have a point to make, you're going to shut people out and not wanting to listen if you're rude or mean about it. I could on for hours about how Buffalo has the greatest chicken wings on the face of the earth, but if I call somebody an idiot for not knowing about them, that's really not going to convince them. Know what I mean?
EDIT: I want to add that if your justification for me being kind to kids and you
not being kind to children is because "it's my livelihood", that's frankly silly and irresponsible of you in terms of building a more open-minded society. You're not going to teach younger people the things you think they should know by telling them they're thoughtless and a bonehead, for lack of a better term.