Assimilation isn't the problem. People should learn the language of the land they immigrated to and learn that there are some things that may be acceptable in your home country that isn't acceptable in the new country you live in.
The problem is many conservatives take assimilation to mean "Drop your faith, drop everything about your culture (don't even think about eating shawarma or an authentic taco ) and be like us ignorant right wingers. They want people to stripped down completely of their cultural or religious identity. Conservatives want a monocultral society.
But I notice it's always the brown immigrants (South Americans and arabs )that white conservatives are always shouting assimilation to. They never check the immigrant communities like Eastern Europeans. Many of them come to the England and America speaking no English and only staying within their own communities.
I find your post very confusing. I live in the USA and you mention the term "brown people" "Brown people" is a british
term. Then you mention South Americans and arabs. I do not think that Great Britain faces a "South American" minority and ----As to east Europeans-----Does great Britain have a significant Eastern European population? Again, I live
in the USA----I have never noted a prejudice against tacos
or schawarma. Your post evinces a bit of prejudice against
"eastern Europeans" Do you actually believe that people who speak Spanish at home are subject to discrimination in whatever country in which you live? How about Polish?
Italian? Polish and Italian is ok in your country?