It's perfectly okay to be pro-free-speech while acknowledging people like this exist. Plus the guy resigned, not hounded into quitting by a Twitter mob.
Plenty of resignations, firings, bans and other things have been denounced as "cancel culture" by the free speech brigade which didn't involve a Twitter mob hounding anyone. But the article says he resigned after "condemnation throughout Utah's tech community." Surely that's cancel culture? The chilling effect of the mob, the jackboot of censorship?
The only reason no one is standing up and giving a full-throated defense of this man's right to speak his mind without consequence is that they're only willing to defend heinous speech in the abstract. Give them a concrete example and suddenly they discover the existence of nuance and sit in the corner whistling Dixie.
I support complete free speech and also law. If some speeches are very bad for society make a law and enforce it. Otherwise it gives random group powers to accuse and persecute without a just trial.
All laws are human made and can be changed if society agrees. Even some kind of "canceling " can be part of law, if society wants to keep the absolute free speech.
From outside, if such emails can create violence then as a society we need to figure out how to develop more non violence in our culture other wise we will be just treating the symptoms and not the cause.
Edited part below:
On more thoughts, if a person is making an accusations without substantial proof, a similar accusations can be made against that person without substantial proof. I think that is fine. However will like that to be in the law and done by proper procedure. Allowing groups to act as mob is dangerous.