Open spoilers for show/books. The events I’m discussing haven’t happened in the books yet so most of that discussion is speculation, hopefully it’ll go down differently.
The Starks aren’t dealt endless suffering in GOT/ASoIaF out of pure sadism. Their story is meant to illustrate that the fantasy trope of chivalrous, honorable conduct doesn’t always win out - that when it’s up against people who are willing to scheme and be dishonorable and do anything to boost their own power over the greater good, their honorable behavior can lose.
In the North, honesty, loyalty, duty, and honor are simply more important than they are in the south. They must cooperate and treat each other fairly in order to survive the much harder conditions. If they played the game of thrones in the north, too many resources would be spent on war and squabbling to have any left over to survive the winter.
So a leader like Ned Stark and his code of honor makes a lot of sense in the North. He’s exactly what they need up there for the conditions.
But when he’s dragged down south, into a den of vipers, and forced to try to maintain rule against people whose traits are duplicity, dishonor, and selfish conduct, his skill set and traits leave him unable to maintain rule and ultimately unable to survive. Okay, this makes sense - this is a thematically consistent point. Northerners are different, and in some scenarios that hurts them. Great.
So in the last two seasons of the shows, we’re given hints that even though the Boltons are in control of the North because of their betrayal, the Northern people resent such a thing, and that The North Remembers. That the people’s loyalties to the Starks run deeper than typical vassal loyalties. We’ve been told explicitly by Sansa, John, and others that northerners are different - more loyal, more honorable.
Since the Starks are the most identifiable “good guys” of all the factions of the story, as an audience we identify most with them and we’ve been punished by seeing them suffer throughout the whole series.
But now we’ve been set up for a well-earned comeuppance, a triumphant moment where the traits of honor, decency, and loyalty of the North cease to become an anchor that drags them down, but a wave that uplifts them. We’re told over over again that The North Remembers, that northerners are different, that the Starks matter to northerners. We’re set up for a well-earned payoff after years of watching the Starks suffer to finally have them win in a completely organic, and earned way.
And… nothing comes of it. None of that matters at all. A few minor houses fight or Jon Snow/Jon Stark, but almost all of them abandon the Starks in their time of need and show no loyalty. “The North Remembers” amounts to nothing at all. The day is ultimately saved when an outside power (Littlefinger and the Vale) come in and defeat the northern armies.
So after years of enduring Stark suffering, and the North suffering, we finally have a way that’s completely set up by the story and earned to give them a cathartic victory, a fist-pump moment where the positive traits of the Northerners finally had them a well-deserved win, and nothing comes of it. Instead we get a cliched “some forgotten outside force comes in at the last second to win the battle” ending.
This is an incredibly botched storyline. 6 years of payoff just completely left aside for seemingly no good reason. As much as the Starks’ suffering was earned given the context of the story, the Starks victory here was also earned.
There were hints it was going to end that way. For instance, when Ramsay Bolton demands a pledge of fealty from Lord Karstark, Karstark refuses, saying pledges are worthless given the duplicitous way that the Boltons came to power. I interpreted this as an honorable Northman finding a reason not to give a pledge that he knew he was going to violate later, since he planned to betray the Boltons. Perfect setup for the Karstarks to later betray the Boltons in a way consistent with their sense of honor and loyalty.
A better resolution, obviously, and one fully supported and heavily hinted at by the story, would be if the northern armies that lined up alongside the Boltons had betrayed them at the start of the battle and fought for the Stark army. Instead, we get the cliched “all is lost… oh wait, here comes the cavalry” ending that we did get.
It also made the following scene in which Jon is declared King In The North ring hollow. Everyone basically had to say “yeah, I was a loyal lacky to the Boltons who I knew were shitbag impostor rulers of the North, but hey, you beat them in battle, so now I’m gonna suck up to you and pretend I was loyal to the Starks all along” - the scene is meant to be a triumphant scene like Robb being declared king, but instead loses most of its impact because the northerners aren’t acting in character up until that point. It robs the Stark of their moral and story victory and turns it into a victory of happenstance - that Littlefinger came to the rescue.
The books haven’t yet reached this point, so I hope we can at least get the cathartic Stark victory there. The North Remembers is more actively shown to be plotted with the Manderlies. But the showrunners do have an outline of how the story ends, which makes me wonder if this was the intended route.
My guess is that they thought the cavalry coming at the last moment was more dramatic on screen than paying off 6 years of story and giving the audience a cathartic victory for their long-suffering protagonists. They were wrong.