What benefits has the U.S. enjoyed due to the absence of persons striving to be a king or dictator?

Two benefits that we have reaped by having eliminated
these means of succession are transfer of leadership without violence and transfer of
leadership based, at least theoretically, on merit, rather than on heredity.  Those who
seek to be dictators usually need physical force to back up their accession to power
and/or to maintain their power. Those who strive to be king (or queen) are generally
staking their claim on a familial relationship.  These benefits confer upon the United
States a stability not enjoyed by many other countries.  Every four years, we elect a
head of state, without violence, based to some degree on merit, and with the machinery
of government firmly intact and functional, which allows it to do its work during the
transition.  Of course, I should also add that there are countries with a monarchies
that also enjoy this stability, those which are constitutional monarchies with clear
succession lines and figurehead royalty.

It is going to be
quite interesting to see how recent events in Middle Eastern countries will play out,
given the ouster or almost ouster of some kings and dictators.  Will provision be made
for leadership and succession that is similar to that of the United States?  Or will the
instability of past mechanisms prevail?  I have included a link to an article that
discusses the idea that some cultures do not naturally support a democracy.  Does this
mean that those cultures are doomed to the instability of the succession of king or
dictators, suffering from the lack of benefits our system
provides?