it's kinda hilarious that you quote someone as being proud of his former country and it's culture as a positive example and then go "who cares about that heritage and culture!"
I guess I didn't put my message through clearly (don't mean this as a jab to you, more at my post)
Personally, I feel pride for many things about the two countries I identify with (US and India), but if in 50 years, the US has a much different culture, to me that doesn't really change much. If the main culture in the US were to change, then that's just how it happened. The US would still be the US, the ethnicity or the culture of the people living here doesn't change that.
I might be giving off a screw everything free borders vibe right now, but that's not what I mean either. My opinion is that people shouldn't be "the glorious American way is dying" about things like immigration and refugees. The sort of statement has no effect on me.
The US and Canada have been founded by immigrants, built by immigrants and have been receiving constant immigration for a century (more than a century if we also count European-exclusive immigration), whereas some European countries have had the same ethnic groups living in more or less the same places for centuries and immigration has just started 20-30 years ago, in some countries it started in the last decade!
Just 40 years ago seeing a black person in Spain was a complete wonder. Now not so much, but it still is in some other countries, like the Slavic states.
Sorry, but without living here you cannot possibly understand how it is. It's not like Americans who say "yeah, I'm half Irish, and half German", but they're still Americans, speak English, etc. Immigrants to the US, for one reason or another, try hard to assimilate and "Americanize", so in the end it is a melting pot, everyone is from everywhere but most people share the same core values and develop patriotism for the country, etc.
That does not happen here, or has not happened yet because in most countries there are only one or at the very most two generations of immigrants, not more. They have not integrated, they speak almost exclusively their own languages and they don't interact with locals. So they become completely isolated groups and there's little interaction between them and us.
And yes, they probably have to assimilate and act and behave like everyone else for people to truly accept them, and it still will take a long time before people here can finally accept as Dutch/Basque/Pole/Dane/<you-name-it> someone who is from a different ethnicity. But I have already explained why is that, and it has little to do with racism or discrimination. See it this way: if I move to Japan and manage to get the citizenship, will that make me a Japanese? No, I will be a European with Japanese citizenship, but not a Japanese person. Because "Japanese people" refers to a very specific subset of people. That's how it works in the old world.
Other Japanese may not consider you "Japanese" but I'd say they were xenophobic for doing so. No, you would be a japanese citizen and a japanese person, and others trying to put limits saying you're not a "true japanese" person are filled with bs. I actually find it interesting that you mention Japan too, given that people criticize Japan heavily on this and how homogeneous it is.
You're also missing the fact that expecting immigrants to assimilate in the 1st or 2nd generation is silly. Where has that ever happened? Integration and assimilation in one or two generations! Even in the US it doesn't happen. Assimilation happens over generations, with newer generations typically being more in touch with the place they 'were born (of course, this doesn't apply individually, there are people and families that I know that don't follow this, but overall that's what happens.
Immigrants are going to situate themselves with communities that they share things with, not down to the country, or the region in the country, but down to the region in the state that they're from. Even the ones that go out and meet people from the area that they've immigrated too, even they will join communities like this.
On your point about Europe's immigration problem being relatively new, sure, that's true, but that's exactly why I feel like people should get themselves out of this "I expect immigrants to immediately assimilate" idea. The truth is, no matter where immigrants are from, you're going to see this.