As with a lot of people here, I found out about hubski from a reddit thread. Though I see now it's nothing like reddit and actually use both regularly.
That said, I generally don't like the content on here. And most functionality acts/works like reddit. So why come here regularly? The people. It feels like a community. Which is surprising, since even my Facebook feed still feels like random strangers posting.
Everyone stands out, and everyone has a personality. Which I find fascinating. There's people like me (down to my Nintendo fanboyism) and there's people that are my complete opposite. Yet, everyone here can chat and discuss things like reasonable people.
The closest I can relate hubski to would be the Transfer Student Center at my university. There's a variety of people who regularly go there, and most people know each other. Though, there's two key differences. The first is the type of people. They are mostly the same. They follow fads, don't have unique ideas, and are all transfer students in a variety of majors. Not that interesting to talk to, but it's okay if nothing is going on. The second key difference, which is important, is that the transfer student center has a major rule of not talking about controversial topics. And it tries to reduce debates/arguments/discussions. While hubski encourages it.
So yea, that's why I "use" hubski. I feel obligated to come, both to share my thoughts and ideas, as well as anyone who may miss what I say. And I enjoy hearing about people's experiences and thoughts, even if they are on the other side of the world.
It really feels like a community here.