... "I think those children suffer and I won't help put them through it."...
My conclusion is that this man means well, and really doesn't perceive himself as a racist, because he has child welfare at heart, but this is akin to saying that certain couples may only marry if they are sterilised, because someone else has judged them to be unfit parents, or has judged their potential offspring to be unfit children.
Yes, the children may
suffer ~ but they may not.
It is not just children of mixed marriages who have problems.
Are we going to ban anyone from marrying, or from having children, based upon the narrow ideas of other individuals?
Even if they mean well, I don't think that this can be a good thing.