Your rationale for using intrinsic motivational strategies to encourage appropriate behavior, but ultimately relying on intrinsic motivational strategies to reinforce learning accomplishments makes good sense to me. As you point out, one has to consider the context and what are the best tools you have available to support the situation.
As concerns Hive and SpringRole leaderboards, I did not directly address this in my discussion response to this week's prompt, but not being particularly extrinsically motivated, I have to say that I did not really pay much attention to them. However, while I do find the idea of Hive's built-in rewards system to be kind of fun, I don't find it to be particularly motivating. As for SpringRole, I don't think the platform was operational enough to make viewing of its leaderboard necessary or meaningful.