From an artistic standpoint I love that they kill a central character, this is not Star Trek, where only the guy in red dies. I like because the Death of a good man, great warrior and loving Father of six children happened and it happened swiftly at the hand of a capricious tyrant.
Such an outcome is in line with my view of the World, the one shared by both the the Ancient Greeks and Romans and that of my own Germanic ancestors (Anglo-Saxon, Rhinelander, Bavarian and Visigothic alike). Life is fundamentally a tragedy, we all die, we all could get killed or crippled or injured at any moment, physical and emotional pain are everywhere, old age is a time of pain and debilitation and is not one's "golden years." If you are successful, people will envy that success and someone is always out there wanting to take what you have There will always be people looking to kill, maim, rape, humiliate, subjugate you and your family (even if you have never meet them or never have wronged them in any way) and that in one form or another Winter is always coming.
I also like how we get to see the ugly and unvarnished world of absolute monarchy and the perils of win or politics. The poverty and insecurity and lack of dignity that is heaped on the shoulders of the masses, the results of the feuds between Aristocrats, is on full display and while this is listed as part of the Fantasy Genre, I hope that GoT thrones might change the minds of people who complain about how bad it is to live in a world of generally constrained government and generally unconstrained economic growth. The blandness and sameness of of our comfortable post industrial revolution, middle class lives are small prices to pay to live in a world where all but a lucky few live colorfull lives of misery, toil and poverty in rural villages and small provincial towns.
It is also one of life's tragedies that this season of GoT is so damn short.
BTW
I do not think that Cierci is worried about the Dothdraki yet. Earlier in the season she told Robert that they have no ships and no armor and no castles (and presumably no siege instruments) or discipline. Ned Stark also said that he would worry about the Dothdraki when their horses learned to gallop over the sea. Also keep in mind that Westros has formidable Naval power, it crushed the rebellion of the Iron Isles so the Dothdraki might have some trouble if the Westros Navy finds them sailing in troop transports and they have no Naval cover of their own.
Cierci was already worried about the battle with Stannis and she wanted an alliance with the North, which she described as too big to be conquered and governed. Even without an alliance with the North, she wanted them to at least just stay out of the war for King's Landing (and she will be even more disheartened to know that half of the Lannisterian forces were destroyed by Robb's army and that Jaime is a prisoner). If she wanted to avoid a war, she should have simply said that Ned Stark could leave, without bending his knee to Joffrey and just go to Winterfell and keep Sansa and Arya as hostages (to keep the North allied or at least be neutral) and when Ned dies, have Sansa marry Joffrey as was originally planned.
