People were always going to be mad. So many hardcore fans have pet fan theories that they want to happen, and many of them are mutually exclusive.

Not to mention the criticisms are all over the place. Some people want it to take 3 episodes to march to King's Landing. Some people want prophecies to be fulfilled in the most obvious, predictable ways possible. Some people want unexpected deaths of main characters to "subvert expectations." Some people want fan service like Cleaganebowl. Some people want long scenes with niche side characters to hear about their backstory for 40 minutes. Some people want all the nitty gritty details of how all the thousands of peasants and soldiers are going about their daily lives. Some people want CGI and spectacle and cinematic action.

These desires all pull in different directions.