I think the steem blockchain will do well as more de-centralized apps build out the ecosystem. However, steemit.com certainly has room for improvement. One big one are the bots that significantly reduce the quality and create opportunities to game the system. There are downvoting wars that continue. Let's see ultimately what changes get implemented to remove some the biggest sources of friction and abuse.

As for steem, I don't think it's success is completed dependent on the success of steemit.com.