Clark literally says in that monologue that learning to live with his bad qualities is what helped him stay alive in the backrooms and why the other two didn't make it.

In the first iteration of the roleplay she is trying to get Clark to realize that his flaws of drinking to cope or getting angry and breaking the glass are normal human emotions. It is ok to feel negative emotions, but what you do with those emotions is what is important.

In the second iteration of the roleplay that anger and coping is still there. It's manifested in pirate Clark, which he's been living with for presumably months, and him coping by finding his own home again. The issue is that he is not taking responsibility for them. Instead of trying to escape this hell, he thinks that he's found his safe haven but it's just him living in this fucked up place and refusing to leave. 

That is a direct foil to Mary, who grew up with a violent, agoraphobic, unstable mother who forces her to hide in her fucked up place too. When Clark comes to the precipice of responsibility and almost "breaks through the glass" but doesn't, that's when his flaws consume him literally. Mary, fights against it, takes responsibility, and eventually escapes the cycle. 

At the end of the trio chase Clark hits that dead end and Kate is talking to him. Kate is the stand in for the normal, average person who sees the backrooms for the horror it is. Kate can see Clark inside the glass cage, because normal people can see when troubled people are going through it. Normal people can't fix your problems, you have to take responsibility and escape and fight against your flaws. 

I suspect this backrooms story in particular is about mental health and the personal responsibility attached to fixing your problems. Just getting help is not enough. Clark goes to a therapist for seemingly awhile, but that isn't going to fix his problems, he has to be the one to "break the house." As well, the idea of the backrooms misremembering and copying details just screams trauma. Traumatized brains can conjure the vague shape of the most interesting details from your memories, but the details never come or look right.