Don't blame Serena for her fans being shitty.Anybody with a fan base knows how their fan base will react when they get into a high profile argument with someone or criticism of them. Absolving her because she didn't cultivate that kind of fan base is just dumb as she obviously has, given that is what her fan base is doing.
Those fans have agency. Those fans can choose not to be shitty. They're choosing to be shitty on their own.