"So why would people post elsewhere where they get nothing "
- Private messaging
- Group messaging
- The ability to control who can see your posts
- Being able to share good content, that someone else has posted, to your followers without being penalized
- Ability to make topic-oriented groups
- Ability to make those groups private for sensitive discussions
- etc, etc, etc
...It's not everyone's goal to have mass visibility and become the next internet superstar. The tools I've listed above are just a few of the reasons why Steemit users keep going back to Facebook even though they get no money for it.
Some of these will be implemented in Steemit for sure, others can be built using steem blockchain but using other sites. But good points and Steemit doesn't have to cater for everyone or try to even.