Hell, even in the show I never agreed about that particular aspect of the ending sucking. At the end of the day, no matter what Dany did on Essos, she was a temperamental child acting mostly on emotion, armed with nuclear weapons. Freeing slaves and uniting warring clans is all well and good, but essos was 100% a might-makes-right culture, and she was acting with the biggest guns anyone had. She was convinced of her own righteousness, and at the end of the day, for all her talk of a fair world, her "grand plan" was always, from beginning to end, to just ride into Westeros and start torching everybody who disagrees with her. That was literally her solution to every problem. And that worked on Essos because literally everybody there falls in line behind the strongest person, for one reason or another. But considering everybody in Westeros' last memory of the Targaryens was the mad king doing EXACTLY THAT, things were only ever gonna go one way.
If anything, the part D&D handled the worst was just having Jon immediately fall for her for no goddamn reason. I mean, by that point she'd done nothing but massacre her way up the countryside and demand everybody swear lifelong fealty oaths. Yet somehow Jon is convinced she's some revolutionary savior? Not inly that, but he's convinced to throw away the wishes of his people, his family, and the freedom his countrymen have been fighting for for years, just for auntie-sex? I don't usually use the word "simp" as an insult, but God damn, son.
I have no doubt the story as written by Martin would be LEAGUES better that the hackneyed rush-job we got in the show. Assuming it ever got made. Which it will not be.