"Merah, on the other hand, had a quincy father but it was long suspected his mother was an arrancar. [u]Was it possible? No, not really.[/u] Did the rumor mongers and haters care and use that as proof that they should stop using possible arrancar blood within him in order to call him a "bastard child" and smear his very existence? Naw. Haters gonna hate." 

He doesn't really have an arrancar mother. They just say he does and use it as an excuse to completely smear and outcast him in the family. It's hate resulting from his father being an arrancar sympathizer like he was.

Edit: Seele Schnider has been removed.