JRRM goes down the rabbit hole of presenting the worst thing that could happen probably will a lot. These decisions don't always makes sense, and depend on the characters being emotional and unpredictable. He mixes horror themes with fantasy, and in those, its a trope that nobody ever does what they should.
Cersi never batted an eye when there were three dragons coming for her. Then they ticked them off one at a time, to make it seem really close. What do they call it when a love relationship has no basis in a story? It's called 'shipping.'
There were several times in the last couple episodes where motivational 'shipping' seemed to occur in the series. I think this is what everyone is mostly angry with: that if the plot was going to go this way, there needed to be linking scenes that made the progression of the story line and her motivation clear.
Danny just kind of comes off as a really wildly varying tyrant who is benevolent on one day, and on another kills everyone in the room and eats their chickens. This seems really odd, but I am not surprised by it. See my earlier comment about painting Brienne into a plot corner in the books with dead Catlyn Stark and Jamie Lannister. Danny just shows us what she is capable of on a bad day.
People talked about the problems for years, and I wasn't really surprised by the ending. When I heard the spoilers I thought well, that just makes sense, based on what he has written before, with scenes like the Red Wedding.
I'm more of a dilemma resolver like JK Rowling. Her books have a main mystery or two in them, and then a lot of little tasks in the scenes that the characters all have to work through together. This is ideal for a young adult book, and it can be pretty smooth. But then the tension is abated, and you have to quickly work into another dilemma.
Martin has a kind of sectioned intro that builds realism, then character familiarity, a belief in innocence and rules, a testing of morals, a build-up of tension, then action and horror, and the dissipation of order. This is the progression he works through in his chapters. Sometimes they end on a really wild scene, and on a down note that is later never worked through. I thought in the books Danny would stumble terribly in Mereen, and then get it all together in Westros, but maybe not.