Maybe I didn't pay attention in film class like everyone else, but I really didn't think this episode was bad.
Yes, things have been rushed, but I kind of expected that when we found out there would only be 6 episodes. How could they possibly tie everything up and slowly develop things in about 7-8 hours? Not that I'm happy about the rapid pace, but I was prepared for it.
Seems like people are unhappy with Dany going mad so quickly... but as was stated earlier, the signs have been there for a while. Even her constantly saying "I'm nothing like my father" was kind of pointing to her being exactly like her father, imo. Also, characters repeatedley asking Tyrion, Jorah, Varys, etc. "are you sure about her?" over the years made me ask the same question.
So having some important events happen to her in a short time (death of Jorah, her dragon, Missandei), finding out who Jon was, seeing how everyone loved him and hated/feared her, being betrayed, etc. would be more than enough to ignite the madness in her. Yes, I agree it happened quickly.... but again, 6 episodes.
I think Dany burning everyone happened for 2 reasons.
1. A "**** you" to Cersei. It's like she wanted Cersei to know that she was responsible for everyone dying, before she died.
2. Dany mentioned that the people in Westeros would love Jon more than her. If the people in King's Landing found out who Jon was, they'd push for him to be in power, as would other houses in Westeros. So she killed them all and will replace them with the people that love her and don't give a shit about Jon.
Another thing people seemed to be upset about was Jamie's arc. I personally thought that was a fitting end for him. All series long, he was a terrible person who did terrible things for Cersei, but also kept doing honorable things as well. At the end of the day, he was still drawn back to Cersei. Spending his whole life doing terrible things for a woman he knew was terrible only to end up killing cersei would have been more lame, imo. This was foreshadowed too.... A couple of seasons ago, Bronn asked Jamie how he would like to die, and he said "in the arms of the woman I love." Obviously the only woman he truly loved was Cersei, and he died in her arms. Throughout the show, they would repeatedly tell each other that it was just them two and nobody else. They died alone with no one else around them. Some people were confused as to why Cersei embraced Jamie after ordering a hit on him.... Well, if the city was burning, all of your protection was dead, and you saw your lifelong lover/brother, what would you do? He was the only one in her corner at that point.
I don't think it's been as good as seasons 1-6, but I'm not upset over it either.