They’ve supposedly known this is where Dany is going since at least season 4 and maybe even season 1. Weiss and Benioff just aren’t good writers. I could see Dany slowly sinking into the depths of madness or I could see her become very Machiavellian and burn the Red Keep, killing Cersei but also all the innocent people there, but burning the entire city, after the surrender, was not true to her character. Not being able to handle being disliked when she was strongly disliked in Mereen for a long time is also unbelievable. No one’s actions this season have made any sense.