Okay, no. Hell fucking no.
People like these characters because they're HUMAN, because they have real, genuine problems and flaws. Some of them overestimate their control of others or find themselves resorting to doing awful things because of what has happened to them. And if they are evil, then they're charming or endearing or entertaining enough that we don't care. On top of that, almost all of them are victims of terrible or dysfunctional lives.
Malty, on the other hand, is a goddamn princess who literally lost the right to the throne because of her bitchy behavior. People in-universe and out hate Malty because she actively, read: ACTIVELY, chooses to dick over people even when it does everything except benefit her and they hate her even more when she doesn't pay for it.
The idea that the girl who was introduced ruining a guy's life and reputation because she could and tried to kill her own sister as a power grab doesn't deserve to be called Anime's Worst Girl crosses the line from idiocy to straight up mental deficiency.

And not one of them had their names legally changed to "Bitch" and "Whore".