" because of the modern way of thinking that it's OK *not* to learn the main language of the country you have chosen to live in. "

My great-grandmother emigrated to America from Sicily in 1904. She died in 1968. She never spoke a word of English.

I don't think it's all that uncommon for the first generation of immigrants to be quite insular and not integrate all that well. It isn't really as easy and straightforward as "If I went to live in France, I'd learn French. If I went to live in Spain, I'd learn Spanish, etc...I think it would be arrogant and spoilt brattish of me to assume that *they* should learn *my* language." There are all kinds of issues around culture, education, the type of society one has emigrated from, etc. There's a big difference between a Brit, say, buying a gite or a Tuscan farmhouse and having the cultural sophistication and confidence to mix happily with the locals; or someone from what may well be an impoverished, small rural community where both education and opportunities to engage with the wider world have been limited. That's the kind of environment my great-grandparents came from. The isolation my nona would have felt was compounded by the hostility she experienced from white Americans, so she tended to "stick with her own", and her social circle was consequently drawn from other Sicilian immigrants: friends and family, and later on her 9 children, their children and grandchildren.

To be honest, I don't imagine that the situation is all that different for many immigrant communities today - it is often fear, and adherence to the familiar, and maybe a bit of hostility (perceived or real)from the outside, which drives insularity. That's the reason that, even now, you get ethnically-divided "neighbourhoods" in cities and towns. The important thing to understand is what happens AFTER that first generation: my grandmother and her sisters and brothers were Italian/American, but very much American. People do integrate.