Judging from some of the responses to Tumblr's new "no porn" policy I'm guessing I was the only person on Earth who didn't use the site for porn.
Hashtag unpopular opinion, but I think Tumblr’s policy change is sensible given the circumstances.
They currently spend a fuckton of resources hosting pornographic content whilst trying to shield it from minors and search engines, and complying with the regional laws of hundreds of countries, and the rules of various online marketplaces.
They probably have a whole team of people whose entire job is to look through images of the most disgusting, depraved stuff to make sure it's not child porn.
The new rules specifically ban real life depictions of sexual organs in a sexual context, and any graphic depiction of a sex act.
Other NSFW stuff is still allowed. Fetishes are still allowed. Erotica is still allowed. Nude fanart of the Onceler is still allowed.
Tumblr also in September introduced new rules that made expressing anti-LGBTQ+ sentiments on the site a bannable offense. I doubt their intentions are malicious here.
Why bother continuing that huge sunk effort and sunk cost, to continue supporting something that isn't even a major component of the site, when you can just… not?