People are using Steem because its UI and UX is great

People are using Steem in spite of (available) UI, not because of it. A common theme between BitShares and STEEM is that while both have incredibly well thought out incentive structures and robust back-end software, the user interface appears to have been developed as an afterthought. Considering Dan Larimer's "ship builder" approach to blockchain development, and the fact that the STEEM blockchain does not ship with a UI in the first place, instead providing the necessary API for the creation of a UI, I can see why this would be the case.

For the STEEM platform to be successful, more resources need to be dedicated to improving the UI and UX. I generally use steemit.com (which is the most mature interface to the STEEM blockchain), and while improvements have been made since I first became an active user, the UI definitely still leaves something to be desired. That being said, hats off to the team at Steemit, Inc for how well they coped with 2017's massive spike in new users.

You are dead on with your other points. Steem needs to maintain a better balance between users that create content and those who consume and curate it - right now, I think this balance is tilted somewhat heavily in the direction of content creators. We need to attract more users to curate, but to do that we need to improve the UI...