Explicitly safe spaces in real life typically aren’t open to having strangers walk in off the street, even if they have a bouncer to throw problematic people out. A single negative interaction might require a lot of energy to undo.
Not everybody works all day to come home and relax by reading garbage on the internet.
Some people do and that’s cool. But some don’t. Some of us like standards and we value our time in such a way that we don’t want to have to read some kid’s revelations about the world now that they’ve read Atlas Shrugged.
But that’s why these networks are cool. We can choose the vibe we’re looking for. Just don’t expect everyone to want it your way.