They don’t “take ownership”. For one thing, it isn’t entirely clear what the term is supposed to entail. It probably refers to that perennial complaint about TOS at such sites, that tend to go a bit overboard and are then misunderstood/represented as some nefarious ploy to make sweet bank with people’s memes when, in what some describe as ‘reality’, they do need some sort of license to show the photo you uploaded.

I recently deleted some things on medium that I wrote years ago and had zero trouble doing it. Try that in some arrangement where you really grant ‘ownership’. “Hello Microsoft, would you please remove the background animation from the BSOD”.

What is really more of a technical detail, the domain name of the site serving some content, seems to take on outsized importance for some people. As far as I can tell, this are not actual creators of content of the sort where it would start being lucrative to swindle them out of ownership.

Case in point: AMP. If Google had, from the beginning, made it possible for AMP content to be served from the publisher’s (sub)domain, opposition on HN would have likely been half as fierce, or less. As we now know with some certainty, AMP really was a ploy to screw over the competition. It’s quite excellent that it failed, but it did so mostly due to people falsely believing they are getting screwed over due to this implementation detail, when really it was competing ad networks who were getting the wrong end of the stick, but wouldn’t have been in any position to stop it except anti-trust litigation.