It might be true that the most valued posts right now are about Steemit, but this is to be expected since the majority of users, especially the one's with the most Steem Power, are mostly interested in Steemit. I think this will change over the course of the next year as more people become aware of the platform. Give it some time. I think we'll see an evolution happen over time where other groups will catch on to it and start upvoting each others posts. I remember when Twitter first came out, it seemed like the only people using it were trying to sell something and I thought, there was no way it could last if the only thing you see on Twitter is a bunch of spammy advertising. There is still a lot of garbage and advertising on Twitter but it seems to have established itself as more than just that now.