They instantly fired them. Where exactly was the opportunity for them to back down? This is what you've consistently ignored in order to justify her firing.
For one, they could have done far, far more to protect their employees from the hate mob in the first place. That was their first and biggest failure.
Secondly, having no social media policy, and then jumping straight to firing your employees with no warning or intermediate steps is absolute fucking bullshit and shows that all the CEO cared about was appeasing the frothing hate mob at his door.
I like how this hate mob is still talked about like it actually existed.
Note, I am not denying any harassment as that would be illogical as it is almost assured as to have happened as this is the internet, instead I am being skeptical about the idea that there was a literal mob of such influence and power that a company folded within a handful hours solely to appease it. Especially considering that somewhere on these sixty pages of the thread we would have seen their frothing posted.
As much as they got angry about it, the Roseanne comparison was apt, as Roseanne wasn't fired suddenly out of the blue instantly for her tweets. Her tweets were used as a pretext for ABC to do something it likely strongly desired to find a way to do for some time.