Computer networking in general and social apps in particular are still young, in civilization's history. We are still figuring this out. Maybe in a hundred years we will have a good grasp of what works. If the writer is right, then Google Plus's lack of traction was from the interaction among several subtle ingredients.
So similar to IRC. As much as I hate their desktop client, Discord is actually ticking all the right boxes for what I want out of social media. Ironically one of these things: broadcasting specific things to specific groups, is something G+ tried to do. If I see an interesting paper, I don't want to share that on FB and have my grandmother making confused comments. But I do have a discord channel w/ some college friends where something like that is appreciated.
At the same time, most of them aren't gamers, so gaming content is on a different channel. I don't even regularly use discord for their VOIP chat (arguably the reason they caught on), but unfortunately it is just easier to use for non-technical people than IRC.
I like this. I'm a Discord user with no real life friends on the service interacting with me, but I'd love to be able to suggest channels that don't exist on the WordPress server I use.