Yes I can think that, because the alternative is thinking she's a moron. The Dothraki would NEVER follow that order. They get pissed when she tries to save a handful of women from rape in season/book 1. Do you really think they would spare a city?

Dany sees EVERYONE who opposes her as enemies. She doesn't want to kill the masters who are responsible for atrocities, she wants to kill them ALL. She sees King's Landing as a city of enemies because it is a city that hasn't risen against Cersei. Dany has a MASSIVE saviour complex and the fact she uses it to destroy slavery is used to make the audience sympathize with her increasingly irrational belief in her own righteousness.