I just don't want to have to learn a new language unless I choose to go somewhere where they speak something different. The corollary is that if someone comes to a place where the predominant language is French, you better learn French or you will remain an outsider. Refusing to learn French and trying to operate within your expat cultural oasis (like a Chinatown) shows, among other things, that you don't really want to be a part of that culture. To the current citizens, that looks an awful lot like you want all the benefits of being there but you don't want to actually join them. Which means the immigrant is purposefully creating a rift, intentionally living as a stranger to the tribe, and perhaps hoping that his cultural cell will grow to accommodate his needs and even compete with the local native culture. Which is reprehensible and threatening to the local native. It is like a knife in the back which you are forbidden from removing.
It is simple. If you immigrate you are leaving the old world and the old life behind. Learn the damn language, participate in the damn culture, or gtfo. You belong wherever you make an effort to integrate.
That doesn't mean you have to give up your history, language, religion, etc. But your kids need to have the local culture at minimum, and you can add whatever else from the homeland that you want. Raise your kids bilingual, great. But don't you dare insulate your kids and prevent them from learning the local culture in favor of retaining only your homeland's culture.
Again, immigration is wonderful. Purposefully creating cysts of secretive counterculture is not.
You think there's resentment? I don't want someone else's life change choices to force me to do extra work. If I walk up to the counter at the shop and the guy doesn't speak French, and I'm in France, I'm going to make the universal hand sign for "get your fucking manager to bring another employee". If a machine has an interface that you need to read in French and you don't know French, you don't get to work on that machine. If you want opportunities - if you want to interact with people and things in the place you are moving to - you need to go through the effort to learn the new language. If you want to know what it says on the back of your milk carton you had better step up to the plate and start working at it. It's impractical to have thirty languages duplicating thirty times the same information on a milk carton. See the DMV for an example of how dumb this gets with just ~10 languages - you have a literal wall of text instead of one sign. How is someone going to be able to drive safely and efficiently if they can't understand an unusual road sign?
Not accommodating a language is frequently (intentionally) misinterpreted as an assault on culture. I'm not advocating going into some other country and telling them what language to speak. But if you immigrate, you are expected to melt into that melting pot and if that means your cultural distinctiveness disappears and barely flavors the soup then that's the price of immigrating. If you cared so much about your culture you would live where that culture is strong. You shouldn't expect to be able to spread your culture by transplanting a cell into an economically healthier culture and feeding off of it.
But let's talk about that assault on culture. Do you need those thirty words for snow or sand when neither are prevalent in the area you moved to? Do you need to maintain traditional cooking practices when it's increasingly difficult to acquire the exotic ingredients? I see people walking along in a full body wrap thing, dyed black or bright pink, or a giant turban, and think: those people give no shits about the culture or people here - whatever their evident ethnicity - and again when I see someone in pants and a shirt I consider him a potential local regardless of evident ethnicity. It's not an assault on a person's culture, it's a defense against the outsider which is ingrained in the tribal sociological structure. If I showed up in that person's country wearing cargo shorts and a big ass cowboy hat, or a woman walking around their town showing hair / cleavage / leg, you can bet we would draw some grim stares.
The goal of immigration is that, while the original immigrant may not be able to fully assimilate, the children will be able to go to public school and have native friends, learn the language as a mother tongue, and have excellent opportunities. If you polled immigrants I think many of them would selflessly say they're trying to make a better life for their families. That's great. But you make that better life for them in, say, America by Americanizing them. The extent to which you take on the local culture is the extent to which you will succeed.
This works in subcultures too. You show up at the punk concert, your Army training, the gallery opening, a factory job, or an office job - you're going to be expected to dress and act in very different ways. If you exclude yourself by retaining excessive individuality and operate counter to that subculture you will be a pariah. Counterculture movements just create their own subculture which members must obey. An anticulture movement will have cultural statements, even if that statement requires destruction of obvious cultural symbols or wildly divergent trappings.
Culture is tribalism. Cultures are organized to identify weirdos, strangers, and the insane - so that these may be approached with more suspicion than your fellow tribesmen. Your tribe represents a departure from the need to be suspicious of every man, it represents mutual safety. A person entering your tribal territory proclaiming his stranger-ness is viewed as a threat to the tribe. If he puts down roots and brings in all his cousins that's an invasion. If your children start speaking his language that's a cultural attack.
All cultures want to succeed, to grow, to expand. More territory and more members means more resources and more stability, more mutual safety. When two cultures butt together a border, a skin is created which identifies the "others" not only culturally but geographically. Accepting cultural invaders means your cultural-geographic territory is pockmarked with these cysts of outsiders. You hope, you desperately hope that these cultural infections wither and die rather than expand and create a new front on the cultural battleground, breaking up your territory, separating you from your tribesmen, depriving you of resources.
And a strong culture can steal from other cultures. We feel safe enough that we can import immigrants because we know that we can destroy their culture and they - or their children - will join us and make us stronger. The mixing of genes is excellent, the taking of ideas, even the contributions from other languages. But these are things we take, not things that are foisted off on us. We like Playstation because it's a good toy and because we don't feel threatened by the Japanese. We like oil because we need it desperately and we delude ourselves on where it comes from; maybe this tank of gas came from Canada or Venezuela. And we feel superior to Venezuela and it's OK that we send them some money for their fuel.
If Venezuela were a superpower maybe we would be unwilling to buy from them - unless we deluded ourselves into thinking we were cheating them, getting an excellent deal. I think that's why we buy cheap and often poisonous Chinese goods. Or perhaps it is an allied tribe, in the case of Japan, meaning that even if the deal is evenly matched we still feel OK about trading with them. If another tribe is our superior, perhaps we are cowed into accepting a trade, or else this is simply the best trade available. In that case we would feel bad about the trade but hope that some day we could grow our culture and overcome them and force them to accept OUR shitty trades! Again, the struggle of cultures vying for supremacy, vying for control, but in reality just trying to survive and prosper and be safe.