Your girl wrote a thousand words about the principles and morality of a corporation without recognizing that the point of incorporating is to render your actions immune from principles and morality.
Substack is not a party, it's a bar. The bar will shut down hate speech when (1) it interferes with the mood (2) it pisses off the bartenders. That's it. Except the more people get to decide when (1) and (2) have happened, the less likely they are to shut down. The whole purpose of Substack's little content moderation is to figleaf their disinterested inaction. I don't even need to read it. Facebook doesn't moderate as much as it should because moderating is hard work. Reddit doesn't moderate as much as it should because moderating is hard work. Everything doesn't moderate as much as it should because moderating is hard work. etc. etc. etc. By saying "we're not moderating on principle" they don't have to say "we're not moderating because we're woefully understaffed" but fuckin' hell Reddit once had one minimum wage "content manager" for 12 million people and I had to explain what doxxing was to her.
Welcome to Somalia. There are no cops. Arguing about what cops should and shouldn't do and when they should or shouldn't do it is all well and good but it utterly misses the complete lawlessness governing everyone's behavior. Coulda shoulda woulda whatever pretending it's a party ignores the fact that everyone is there through craven opportunism and nobody has any leverage. You can ask to speak to the manager? But they're not even really sure who has the Conch. They just skim a percentage off the top, man.
There's only one product, your choice is how you pay for it. Medium, Substack, Facebook, Longreads, Patreon, whatever if you wanted editorial vetting you'd buy a newspaper. Except oops they're all dead because information wants to be free.