Instagram and Snapchat made names for themselves by being novel, simple, immediate... You can explain in one sentence to your friends what's cool about them: "you can make your photos look great and see your friend's photos" and "you send quick selfies and they're deleted in like ten seconds so you don't have to care so much".
This hello.com seems like a much broader kind of "social network" that I would have a hard time getting any of my friends or family to try, I think.
Younger generations have a very different relationship to their devices than someone born, say, in the 70's or 80's has.
They care very little about websites.