On occasion, a multiculturalist will treats it as acceptable to oppose mass nonwhite migration if you worry about decreasing wages or losing your job but unacceptable to oppose migration and multiculturalism for every other damn good reason.
So opposing migration and multiculturalism because of crime, dysgenics, genocide, corruption, ruined schools, congested roads, cultural destruction, increased pollution, wrecked nieghborhoods, anti-democratic practices, militarization of police, loss of trustworthiness, loss of speech freedoms, one-sided mass media, divide-and-screw practices, ever more hostile de facto colonial rule, multicultural incitement of antiwhite hatred, and so on is treated as inherently off limits for no good reason.
So let's say your daughter has a mixed race kid, then she is predictably abandoned. Your daughter then follows her next whim, leaving you with the mixed race kid, who will in many cases grow hostile toward you and other whites (peer cultures trump nurture assumptions). And while you are raising the grandchild, in all his insolent glory, you probably will be experiencing excruciating health problems. But only a "bigot" could oppose such dating and breeding, though you are harmed far, far worse than losing a job. And multitudes of other results are even worse than the grandparents being cuckolded scenario.
But all that ethical evidence is treated as worthless or offensive because most people care less about evidence once issues shift from the more pragmatic and technical to the more ethical.