No one has publicly said why she was fired. We only know it happened rapidly. It happened shortly after a Jesse Jackson AMA that went way off the rails, but that could be coincidence.
Is it speculating or finding out the truth that would do harm in your opinion? Her firing is at the very center of a very public controversy - why should it be a secret?
Victoria is most likely legally barred from speaking out, so the facts would need to come from third-party witnesses.