Yeah, I saw Mad Queen Dany coming a mile away precisely for those reasons. If you want to justify your atrocities against your enemies, you have to make your enemies atrocious. And in this case, the audience found the masters deplorable and abstract, so we were able to cheer Dany on. But when she came to Westeros to contend with characters and a culture the audience had grown familiar with over the course of the story, it became harder and harder to accept Dany as a hero. OK, we know Lord Tarly was a dick; he wanted to kill his son, but Dickon was simply a son standing behind his father. The Lannister soldiers were nameless and standing behind an enemy, ok, it's war; people die... just like Tyrion, like Jon, like Varys, the audience still had their blinders on.
But even with all this, from a storytelling perspective, the crazy switch came too fast and too soon. And compounded with the other characters who arcs essentially turned out to be circles
(ahem, Jaime -- what the fuck you mean you never cared about the innocents?!!!? The story we were told didn't support that in the least) the frame made this about-face seem erratic and more about shock value than a careful, narrative cultivation.
Thematically, we were told what story D&D were trying to tell. That life often doesn't follow a story structure or rhyme or reason. People die in unsatisfying ways all the time.
Exhibit A:
Note: The bells sounding at the end of this clip.
Still, you're telling that story with a story, so you have to follow structural rules to some extent. You have to prep the audience even if you mean to pull the rug out from underneath them.
The simple fact of the matter is that they've rushed this season. I don't have a problem with the final outcome of the story. It's just the journey there wasn't satisfying. We weren't given the groundwork, so many in the audience lost their footing.