You do realise that the models stole the art from people all over the world, yes? It’s not like someone in Indonesia drawing fan art can simply profit off their own work the way people like you now can.
I also think this attitude (“just get a job to support your hobby while I get to profit of your work”) shows an overall lack of respect for artists.
Sadly, this is normal online. Many people with some sort of exposure online will receive death threads. Some communities are more prone to it than others.
Pokémon, Sonic, Osu! and many Gacha Game communities, for example, have an unusual amount of crazy fans. When you attract their attention you will become a topic in their communities.