Maybe because we let our vulnerabilities show...In the big real world the paradigm that's running is about hiding, suppressing your emotions, if they are not conforming to the rational expectations of the situation. And emotions usually aren't because this is how they work. It's obviously not okay to let them rule you (well, I still need to learn how not to..) but what is considered "normal" out there is something that gradually creates a lot of invisible pain in people because there is this need for emotional freedom of expression that is denied by how society works. So it builds up. Also, some of the negative, destructive tendencies are considered the norm, and even desired, such as invalidations learned by children early on as the social standard. It's polite to say "I'm fine" and to lie about a bunch of other stuff. You either get used to it and lose the capacity for compassion or you will get fed up and end up feeling like a alien that has lost her mind especially working for a long time in a relatively impersonal corporate environment, where this is the desired standard (drawn from my recent experience...)
Unfortunately I'm also struggling with expressing compassion, because it doesn't come naturally to me...But here I feel safe to at least try.
Here, it's okay to be vulnerable, it feels safe(er).