some royal families do that to keep the royal blood pure. to
have children with commeners dilute the royality. however, this
results in inbreeding, leading to morons and freaks due to the
emergence of weak genes.
there is a good reason why incest is no good and is discouraged in
many societies. it helps to introduce diversity into the gene pool
and prevent problems that arise from inbreeding. the wisdom from
the past should not be abandoned.
