One of the better episodes of the season. I have no idea why people think Dany's snapping was too sudden. It's been hinted and her character developed to it for many seasons.
"The more the better"
Thi is the approach the writers took on this one.
You know, like when Michael Bay made the first Transformers movie and thought: 'You know what? People love explosions! yeah, if we put more explosions people will love the movies even more!"
So these writers sat and said:
- "You know what? People love to be shocked. What can we do to shock them even more? I mean, we have already beheaded our seemingly main character. Then we slaughtered our new seemingly main characters while stabbing a pregnant lady in the guts. And then we burned a little girl on the stake. I mean, what could we possibly do that would top that?"
- "Well, we could have Dany attack the Red Carpet, killing in the process hundreds of the civilians taking shelter in there"
-"Nahh.. We NEED MORE"
- "Ok, how about after ringing the bells and the city surrenders, Cersei gives the order to activate the traps with wildfire, killing most of Dany's troops, causing Dany to completely lose it"
-"That sounds cool. But not shocking enough. We NEED MORE"
But it turns out the more is not always better. Just like you, I was totally expecting Dany to snap, but when it happened I was like: "Really? this is the best you came up with?. Sorry but to me the whole scene seemed so cartoonish that I just couldn't stop laughing at it.