I think the main difference on this front between book and show is that the books have pretty much never shown Dany as a good or stable leader. She's literally a child that's learning by doing and her attempts at being totally benevolent backfired completely when Yunkai pretty much reverted back to how they were the second Dany left, so in Meereen you already see a much less forgiving and more violent side of Dany that, if left unchecked, can pretty much only lead to disaster. Pretty much every one reading the books knows that if the books are ever finished (lol), Dany will more than likely be a villain than an ally.
The show, on the other hand, constantly made Dany into a good and righteous person. Sure, she burned some people here and there, but the show always made the argument that these are bad people that needed to be burned and honestly those violent bouts were always offset by Dany being benevolent and genuinely helpful in the next scene. So when in the second-to-last episode episode the show went 'woop, she's gone full genocidal maniac now', nobody bought it. Even when the show (and some fans, also here on ERA) tried to clumsily defend it by saying "Well, she has murdered people in the past" and "Varys once said the thing about coinflips", nobody really buys that as proper set-up because, well, there was no proper set-up. It would've been if the show actually had followed the books with Dany's arc, but they didn't and the final twist didn't work because of it.
