The king was basically immortal up to this point, no point in having an heir if you don't need one as an absolute godking who has no plans to relinquish his seat of power. Undoubtedly he wanted daughters to groom for his own enjoyment.
Its certainly a pessimistic end, the young boy who seemed to care for her turned out to not be much different from the rest.
I could see some real potential for the type of ending this could have gone... I dont know if it was creative bankruptcy or what but this ending lines just as well...