Even if you can get these people on board it may not help in the short term. When the Tsu site started they had people like William Shatner, 50 Cent, various models and other celebs. A lot of them gave up fairly quickly as I suspect they just didn't see it having a big enough audience to be worth it to them, even if they could make a few dollars. It's a chicken/egg problem with building an audience without having the stars who would bring in new people.
I think Steemit has some issues in lack of features and usability that will deter non-technical users. There needs to be at least an FAQ page to help people get started.
Agreed, but better to have the problem of users, than not. Social sites live or die on user contributions. But, you make a good point. There must be quality and value for the users for them to stay. Longevity is golden.