Welcome back to SJW-niversity, where I'm going to teach you how to strip the obnoxious term "safe space" of its power. It's easy to do if you remember a few things about the way progressives communicate.
First of all, let's recall from earlier forays into social justice warrior-ology that SJW's are essentially larvae who will grow up into establishment liberal politicians and activists one day.
Next, recall that in order to camouflage their agenda, all liberals use euphemisms to normalize their ideas. They cannot just walk up to voters and say, "We're going to take some of your money, keep a large percentage for ourselves, and give whatever's left back to you in the form of inadequate and unreliable 'services.'"
Instead they say, "Taxes are the price of civilization."
The social justice warrior also uses euphemisms, but in this early stage of their life cycle, their attempts are crude and esoteric. You will never hear things like "whitesplaining" and "trigger warning" and "microaggression" and, ironically enough, "social justice" coming out of Hillary Clinton's mouth, because language like that confuses people.
"Safe space", however, is a noteworthy exception because it's an example of a euphemism whose meaning has been further mangled by SJWs until your average establishment liberal doesn't even recognize it anymore.
A safe space was a designated space for people to do what they wanted, and everyone was fine with that. Nobody's going to criticize you for wanting to identify as the letter R in a designated space, or to meet up with other, similarly minded people who want to identify as the rest of the alphabet.
Now, however, safe spaces are public spaces, where your desire to identify as a letter must not only be respected, but encouraged by all other members of the public, and where disagreement with or confusion about your decision to identify as a letter must be suppressed or punished.
SJW's do the same thing with "consent". Whatever consent used to mean, it now means that any pre-existing agreement can be overturned for any reason or no reason at all, and that whoever feels like they didn't get what they wanted out of the agreement can accuse the other party of violating their consent and pursue any manner of action against them.
(By the way: The fact that SJW's have taken these terms and corrupted them is entirely the fault of mainstream liberals. It feels so good to say that!)
So now that we have established that the term "safe space" no longer accurately means what it was originally supposed to mean, we can now call it what it is:
A breeding ground for radicalism. Perhaps it always was intended to become a breeding ground for radicalism.
Now once we have defined a safe space as an incubator for radicalism, a whole lot of stuff begins to make sense.
We see how multiculturalism encourages radicalism by creating "safe spaces" where illiberal practices are allowed.
We see why university educated leftists are unwilling to condemn human rights abuses in (insert country here) by radicals -- because these leftists are themselves radicals.
We see that "education" -- contrary to SJW doctrine -- promotes intolerance instead of combating it.
We see why SJW's are so sensitive to criticism -- because they are like the fundamentalists who will not tolerate slights against their God.
We see why SJW's and fundamentalists share beliefs in conspiracy theories.
And, finally, we see that SJWs wanting to create safe spaces comes from the same place as Donald Trump wanting to build a wall.
In conclusion, defining things for what they are shows them up for what they are. Pretty simple.