The most valuable currency is a user attention nowadays. Clean design, dangerously simple flow, one-click-to-pay solutions, catchy slogans etc. The concept of mentor-mentee can't even compete with today's standards. It requires too much people's effort.
I believe the gamification is a topic worth exploring, but I see it as a second step.
We have not even solve first step limitations. Simple account registration issues, lack of content discovery engine, we do not have even fully-working UI.
Why do we expect people drop their services for the sake of worse solution, like STEEM? Privacy? Latest Facebook case shows it is not a problem. Freedom of speech? Vast majority does not care. Decentralisation? Yep, cool.