You could say the same of Medium, Twitter, Facebook, Reddit, and everywhere else people post content that’s wrong/politically unpalatable.

"Crackpots often use modern communications mediums to publish their insane ramblings"

You would prefer a centralized and curated old-school publishing mechanism.

I've never met a normal or relatively normal person who viewed Substack that way. Most people have the knowledge to separate a handful of blogs from the way a site runs.