Maybe I just wanted an antagonist who would actually sabotage a peaceful end to a problem that has been going on for centuries, someone who is blinded by their own hate, bile and belief that her child, not the one whos already a man grown and one of the best diplomats Westeros has ever seen, will be the one who can deal with the Clansman problem.
Maybe I just wanted to give a reason as to why she really doesn't like you and sees you as a threat to her own child, believes that the only good clansman is a dead one, and views non andals as Barbarians or savages because she's highborn, from a high and rich house, who has absolutely no idea how the world truly works.
You know, the kind of people who should have no fucking business in politics, diplomacy and such, because they know nothing of the true situation, or how to fix it with subtly. Or even in such a way where the knights of the Vale will be able to fight it without losing tens of thousands of men in the resulting guerilla campaign that will follow.
That omake was to show you her shortsightedness. Her terrible superiority complex, and her racism against the Mountian clansman.
Is she right to have it. Certainly, the Clans have done some terrible shit over the last few thousand years. but that does not mean you, have to have the same damn views.