Oh, isn't it just delightful how Daenerys is painted as a whiny, self-important murderer simply for daring to fight against the heinous practice of slavery? But of course, in the very same breath, I’m hearing impassioned defences of upstanding citizens like Aegon the Usurper and Aemond the Kinslayer. Because nothing says “honourable” like usurping a throne and slaying your own kin, am I right?
Daenerys is entitled for wanting to go home, the Starks are not, despite wanting the exact same thing. Oh, and Daenerys must pay for the wickedness of her ancestors, but the Starks don't need to pay for theirs. She must die because the Targaryens are the most despicable family in Westeros.
After all, Aegon the Conqueror conquered Westeros, but the First Men, Andals, and Rhoynar did not. Obviously, the Starks never committed any genocidal acts – they simply asked nicely for the land they built their castles on, and those who sing the song of the earth retreated into the forest of their own free will. It definitely had nothing to do with being hunted to the brink of extinction.
And as for the Warg King and his family? I mean, maybe the Warg King and his sons and his greenseers and his beasts just conveniently dropped dead, and perhaps his daughters married the kings of winter because it was true love. These were surely happy marriages and not a case of killing the man and his sons and taking his daughters as prizes.