I guess, someone with a copyright background came knocking at their door. It's one thing to defend against a lawsuit if you are a big for-profit company with a well-funded law department and a nice financial buffer. But it's an entirely different thing if you are hosting a non-profit platform with your own money because you are a nice guy.
Tbh, I am negatively surprised how many people don't understand that the person hosting a lemmy instance is someone who does it as a hobby and not a big corporation.
The good thing about Lemmy: if you don't like an instance or it's admin, you can just host one yourself. You just need a Pi or an old laptop and a few hours of time. Did you try that?