User blog comment:QueenBuffy/Season 5 returns!/@comment-26158496-20150412214936/@comment-5014364-20150412215358

...I always thought the Myrcella in Dorne stuff was interesting in the novels, and they're expanding it in the TV show -- in the spirit of the novels, I hope -- and I'm surprised at how many book-readers weren't as interested in it (people burning through the novels only focused on the initial Starks and Lannisters, but it's really a sprawling cast of characters)

...the Sons of the Harpy are the insurgent movement of the slave-masters who resent Daenerys freeing the slaves. They're not really anti-heroes throwing off a foreign occupation. They're tyrants and Daenerys had to intervene to spread freedom to Slaver's Bay.