I definitely would not want all internet forums to be moderated to "safe space" standards, but I think it's perfectly reasonable for safe spaces to exist for, e.g., victims of rape/abuse/other trauma who have actual medical PTSD that they'd prefer not to trigger.

The thing is, these are different goals. There's no reason to assume that a goal of "we don't want to host a forum exclusively dedicated to egregious bigotry and bullying" will necessarily morph into "we demand that all our forums be safe spaces for PTSD sufferers." You might as well say that, I dunno, installing public security cameras on a college campus will lead to the students being escorted to recess by a hall monitor, and given detention if they're not in their seats when the bell rings.

I'm fine with "safe spaces" existing. I have very little interest in helping to create a world with all the edges filed off because a few people can't handle the sharp parts. Reddit seems to explicitly be searching after the second, using the language of the first, and there are good possibilities for it to all go downhill.

I don't care, though. I have never found use in reddit, except as an example of how putting people into internet echo chambers turns them into reference-spouting cliques.