Attitudes and behavior like that are signs of deeper issues that have nothing to do with the targets of the person's conduct. This isn't simple jealousy or giving up because they're frustrated. Something made them this way, and it isn't your responsibility to be their emotional punching bag when they're going through an episode.
I'm a healer. It's easy for me to allow people like that to suck me into their issues because I don't like to see someone hurting if I can help. The problem is that too often, these are the types that become emotional vampires.
It isn't intentional. They just get tired of hurting by themselves. When you allow them to hurt you, it takes some of their feeling of helplessness away. They feel a bit of power over their lives. You can't imagine how many YEARS it took me to learn that. Even after I learned, I still couldn't stop being their proverbial "whipping boy" because this relentless healer inside of me made me feel guilty if I walked away.
Let me tell you now: There is nothing wrong with walking away.
See, I finally learned that people like this will never heal or learn to grow if people like us keep being their coping mechanism.
When he's ready to admit what he's doing, he'll seek a better way to heal. He may reach out to you again. Or he may not. Either way, it's his responsibility to figure himself out. If he approaches you after he's done so, be cautious but be compassionate. It won't be easy for him to say sorry and probably embarrassed for the way he acted.
I'll tell you something else: Being angry at these people is still giving them your energy. It's doing you no good.
As for the others who were enjoying all of this, that's disturbing. Those are the people you truly need to avoid.