I had the same thought. Once @steempress-io will be able to embed the Steem blockchain comments onto a Wordpress blog, the game will change.
Right now bloggers continue onto Wordpress, because that's where their audience is, that's where their brand is.
But if instead of Facebook comments you get Steem comments and you have a monetary value assigned to the votes, people will start to join Steem, both for the reward and to keep interacting on their favorite blogs.