@danluu
Re Tumblr: I'm not disagreeing with your overall point, which is that "removing porn killed Tumblr" is unsupported.
I'm confused by some comments evanelias is making -- he seems to think that because most Tumblr content wasn't porn to begin with, this didn't affect most users.
Something evanelias does not seem to think, but which I think is true -- sites that moderate "adult content" are scary to LGBTQ people.
It's common for sites to spuriously rule that content containing LGBTQ people (even if it's not sexual) is porn. Or at least brand-unsafe.
From that POV, allowing porn is a trust-related issue. If you're LGBTQ, you want to be on a site that commits to continuing to distribute your content even if it is ruled brand-unsafe.
Pretty much whenever a site does this kind of thing, the friends of mine who are still on the site start asking themselves "Am I going to get kicked off next?" The people I personally knew who were still on Tumblr all jumped ship at the same time for this reason.
But, well, my friends could be weird.
This is heavily anecdotal. I don't know how big a demographic "LGBTQ people" was on Tumblr, or how universal this fear is. I do know that in 2021, Tumblr's marketing team published the estimate "1 in 4 Tumblr users are LGBTQ" -- keeping in mind that's _after_ the decisions that the meme-category critics are blaming. And also keep in mind that it's a number published by marketing and hence kind of meaningless.
I'm actually pretty sure evanelias was in a position to know all these things and I really wish someone on HN had asked him. In theory I expect this was raised to him at some point. It's kind of an obvious thought when there's at least one gay person in the room.
Admittedly, my consistent experience with straight product designers is that they presuppose marginalized groups are too small to be part of an explanation for anything. There's a particular kind of knee-jerk rejection that I've gotten really used to again and again. Based on that experience, I have a gut feeling that this theory, even if someone raised it, probably was not seriously investigated.