The problem with learning an ancestral or “heritage” language is that it takes just as much effort as learning any other language, except that you get no credit whatsoever for doing it well (and it’s happily assumed that you basically got it “for free”, effortless, in a native or semi-native childhood environment), only derision for the slightest error or weakness 1. And then, as if to add fly flakes to the maggot noodle soup, any errors or weaknesses in your actual native language are presumed to be due to interference from your supposedly native heritage language. Wunderbar.
So next time you meet a Japanese-American who speaks Japanese, give her a hug and a medal. She didn’t come into this game with any advantages; she wasn’t “born into” anything; she deserves it just as much as you. She deserves all the condescending praise that you do. That her family name is “Kobayashi” is virtually meaningless — just listen to the way she says it: “Coe-ba-YAH-shee”! Remember that the poor creature is an American first; she was born in America, as were her grandparents and their grandparents.
Most native speakers of English today do not have any significant English ancestry. But they generally suck painfully hard at any of the languages to which they actually have an ethnic connection. Have you heard guidos (is this a bad word? I hope this isn’t a bad word) speaking Italian? Asian languages are no different. Blood is no advantage, because (wait for it)…there’s no language in your “blood”. Nobody bleeds kanji. Every language is learned from scratch; no Goa’uld genetic memory for you. So, in a way, no one has a birthright to any language, and so everyone has an equal birthright to every language.