Friends, Westerosi, Dornishmen, lend me your ears. I come to bury the Sand Snakes, not to praise them. The evil that characters do lives after them, the good is oft interred with their bones; so let it be with the Sand Snakes -- this is their eulogy.
When the Dornish were first cast ahead of Season 5, they came with much fanfare in the wake of Oberyn's brief but shining time in King's Landing. Doran Martell would be played by sci fi legend Alexander Siddig, to go with Indira Varma's Ellaria Sand, who had such credits as Rome and Luther. The Snakes themselves had illustrious actresses such as Keisha Castle-Hughes, who at the age of 13 was the youngest girl ever nominated for a Best Actress Oscar. What could go wrong?
In the end, just about everything went wrong, unfortunately. The inclusion of Dorne in Season 5 was Game of Thrones making the exact same mistake as George R.R. Martin when he took A Song of Ice and Fire south to the seventh kingdom in A Feast For Crows. Moreover, the way these mistakes played out on screen, versus on page perfectly encapsulated the storytelling weaknesses of each.
For Martin, Dorne was all about Doran, who sat and.... did nothing. He sat and thought thoughts, some of which subtly hinted at so many fan theories you couldn't believe he thought about them all... all while doing nothing, forcing plot momentum to a standstill.
For the show, they took the Sand Snakes and turned them into angry, skimpily dressed soap operatic little sexpots with embarrassingly "ethnic-ish" accents. (And people wonder why there's a huge backlash at Benioff and Weiss writing Confederate.)
Despite a nation of fanboys to hold them back, nevertheless, they persisted. Castle-Hughes may have been given appallingly ill-fitting robes that looked great on Pedro Pascal's Oberyn, but looked like a little girl playing dress up on her, and made it work as best she could. And Jessica Hardwick, who has gone on to be part of the Star Wars cast, as well as the only thing worth watching in Netflix's Iron Fist, did her best with with a whip. The few times they were allowed to have their kills, they did so with aplomb.
Castle-Hughes, who was a huge fan of the books, and Hardwick have been diplomatic about their time on the show, aware that even badly written parts on Game of Thrones gains them more name recognition than headlining most network pilots. They deserved better than they got, dying in the least glamorous ways possible -- having their one character identification (their weapons) used against them.
Maybe when it comes time to remake the series in 20 years, the Snakes will finally get their due on screen. Or perhaps those showrunners will wise up and not go to Dorne at all.