Because the family was separated. The white man was left alone while his colored wife and colored child (who was a citizen) were taken away without him getting to fight against it. That man’s rights as a father were stripped from him too, all because his daughter happened to have an immigrant mother.
Again, the definition of “illegal” is very nuanced. There’s those who come in undocumented. There’s those who overstayed a visa. There’s those who got laid off, and their visa expired while they searched for a new job. We need to understand the circumstances on a case by case basis. We can’t just go “illegal. Not illegal, illegal, illegal”.