Meh... I know what you mean, and I've seen that happen quite a bit. Even my own wife came on here (and she's a prolific blogger and content creator; former magazine publisher), posted a bit, had some $25+ posts and then just stopped.

I think it's mostly about "the burn-in period." Even though that's inherent in ALL social media, people lack patience and stick-to-it-iveness. And someone comes here with 8 years already "invested" in Facebook, or Instagram, or twitter... the response here (monetary or otherwise) looks "paltry" by comparison, and they have long since forgotten that it took them eight years to build those followings. And they get 70 "likes" on their FB posts... and Steemit-- however promising-- just looks more like a chore than anything.

Complete newcomers post... and see some long-time Steemians making $100 for a post, compare it to their own... and think "but mine's BETTER and I only made 17 cents!" and get discouraged... forgetting that the poster who got $100 has 1700 followers, while they only have 14.

I might ask why I am personally an "exception." In my case, I had recently "abandoned" a couple of niche blogs and web sites... so I actually had "space" to develop a new outlet. This is an "instead of," rather than an "in addition to" space for me... it isn't that, for most (I think).