Logically, its also the only thing that can make sense.

The Asari have been in the galactic scene longer than humans have, but other races still treat humans as looking strange despite Asari looking near identical. They've also all been breeding with those Asari all along.

So if it isn't the case, then Asari just evolved knowing that white human female was the de facto most attractive thing in existence and every other race just didn't see the connection.