I suspect part of the retention problem is that:
Creators cannot see the amount of views their posts receive; subs, comments and upvotes are nice feedback, but, if you don't know how many Steemians have actually viewed your posts, it is more difficult to gauge the metrics--and the aesthetics--of the community's response to your work. I think we contributors want to know if our voices are being heard, instead of not knowing if we're yelling into an empty auditorium.
I have invited other creators to join Steemit and they have told me that it is discouraging to open the Trending page and inevitably see the same "content creators" dominating the opening page with mediocre content; many times, the content of the most successful posters on the Trending page is not original work and has obviously been thrown together quickly to serve as a pretext for gaming the business side of Steemit. I understand the necessity of the crypto-speculation here, but I suspect many people did not join Steemit primarily with the intention of earning cryptocurrency; some of us do not want to deal with the unsettled issue of taxable income from cryptocurrency. I'm sure governments will somehow find a way to track purchases if not crypto-income. I joined Steemit because James Corbett had mentioned it in one of his videos on YouTube. I expected to find a great deal of high-quality content and a smarter community at Steemit and I haven't been disappointed with the quality and the wealth and variety of our contributors. Again, however, the amount of substandard posters who end up usurping the Trending page by buying upvotes, etc. really diminishes the standards for content, in my opinion. I have never seen James Corbett or Really Graceful--two reliably high-quality content creators--on the Trending page. I have, however, seen high-content creators like Chbartist on the Trending page--four times on the same page!
I hope this makes sense!