How is it unfair to be considered what your father is? And who says you disregard what your mother is? Nobody, you just put that into the equation.
Islam = father's lineage
Judaism = mother's lineage.
In most cultures, the tribe is carried on by the males side, so if he gives birth to daughters, then she will be what her father is. The boy carries on the tribes name, or the family name, that's why you see boys being so prized in many cultures because no matter who they marry their kids will be their tribe. As for the daughters, they're usually given a man, most likely of the same tribe, so she can give birth to kids that will carry on her tribes name. Sometimes though, a woman is disowned because she ''married out of her tribe''. And why is that? Because the kids won't be of lineage, but of her husbands.
This has nothing to do with nationalism or racism, who says one feels superior to another person or hates another person based on race or nationality? Lol, you're just following your father's lineage (I think the word you were actually looking for was ''tribalism'', but even so, that doesn't
fit what we're talking about).