Pretty simple... no one gets to choose anything about themselves at birth.

You could have been born in Peru to a devote catholic family and you wouldn't have a single thought like you do now. It is complete chance that you exist as you do.

Your ideology doesn't account for the fact that no one chooses their birth or upbringing. You want to separate or oppress anyone not like you... yet what "you" are isn't even something that you ever had control over.

Fascism rejects reality in favor of self-centered protection. It's all about protecting things that you never had control over in the first place. It is illogical servitude to attributes of the self that you never got to pick.