I think 'belongs to Pegida handbook' in itself doesn't say much. It would be ideological (as opposed to evidence-based) political correctness to avoid stating the obvious: it is almost impossible to absorb huge volumes of immigrants, especially when a country has been largely homogeneous and insular for hundreds, if not thousands of years. It does behoove new immigrants to learn the language of their adopted countries. This does not have to be at the expense of their native cultures, insofar as it doesn't run contrary to humanistic principles (e.g. mistreatment of women and FGM are both 'cultural' and 'religious' for sure, but they still have to be repudiated.)