Why the assumption of patrilineality?

heavenscalyx:

Thought for the day: Why does everyone assume that Kylo Ren’s birth name was Ben Solo?

Do we know that the people of Alderaan and Corellia are patrilineal? What if one or both are matrilineal?  Leia’s (adopted) mother was the goddamn Queen of Alderaan.  How could a smuggler/military dude’s name be more important than the Organa family?

There are cultures on Earth that make a practice of using the more important/influential/wealthy family’s last name.  Why does everyone assume that civilizations in Star Wars, a universe where names are magnificently fluid for a high-tech, high-surveillance society, are not nearly so pragmatic? 

Han’s line in the movie, where he responds to the question of whether he was Han Solo, was, “I used to be.”  Proposition: Han actually took Leia’s name when they married, and he became Han Organa, at least until he left.  And therefore their son (who hates his father, remember?) was Ben Organa, until he was dragged off by Master Voldegollum and changed his name.