And it also makes them indistinguishable from countless thousands of other immigrants with the same barrier who come in, learn the language and end up prospering.
"Prosper" is a bit of a stretch, but regardless, how quickly immigrants will learn the new language enough to "prosper" will be impacted heavily by the overlap in the languages. Spanish speaking immigrants to the US are only having to learn a language with the same alphabet, where most words have the same roots, and where a sizable % of the people in their new country have at least some familiarity with their native language. None of those are true of Arabic speaking immigrants who not only have a different alphabet and different word roots, but the language is written and read in the opposite direction (right to left).
I'm not offering this in support of credoconsolans main thesis, just pointing out that adult immigrants with latin-based native languages can pick up on English and communicate with Americans a whole lot easier than immigrants who only know Arabic.