When the author sees that twitter and reddit both have iOS apps, he handwaves it away as a mystery why they are allowed to exist on iOS. Doesn't this go directly against his claim "no modern internet service in 2022 can have the rules that Tumblr did in 2007"? They are literally the direct competitors of Tumblr, and they didn't alienate a huge chunk of their audience with strict content policies.

Maybe he wasn't part of the organization at the time, but Tumblr was removed from iOS for a widely publicized child pornography incident. They made an internal decision to axe any and all adult content as a PR response. The app store did not mandate this.

(edited for clarity)