Are they seriously abandoning their account to make comments on reddit that will never earn them a cent or collect curator rewards on another site that doesn't yet exist? Steemit is the only game in town (that pays in something other than karma hugs) and likely the payout today will increase over time if the site is successful--so either these people are irrational or full of shit.
If they are the 1.3 billion from Facebook, they aren't likely using Reddit either with its 0.16 billion usership. There are so many different things that users can do on Facebook. Steem is so one-feature-wonder.
And my point is the monetary payouts are not important to most users (because they aren't significant).
The concept of Steem has some upside, but fully leveraging the conceptual model is going to require a lot more development work.
The developer of Steem is one of the most talented in crypto so if the Steem vs. Reddit model worked they could certainly rapidly develop a Facebook type extension on the same principles where the most popular content is rewarded. (You could actually create any model that paid new users for sign ups/content/other and in the process attract lots of new users and look like you have a popular and growing site.)
The question is how sustainable is the business model?In contrast to tokens like BTC that aim to be adopted as a form of limited money which are also reliant on some new demand to offset new supply like Gold, Steem is a company share, with VERY high inflation & a large percentage controlled by the founders. Unfortunately the company Steemit has no actual revenue source. It is paying it's expenses (New Steemit users & their content) by diluting Steem holders at >0.2% daily. In that sense it's a pyramid scheme, in that it is a company that sells no product or services and is reliant on new Steem speculators to pay out new users and content rewards.
Once speculators realise this, demand should decline and at some point it is mathematically inevitable anyway...
Because at >0.2% a day you'd have to believe Steem will increase by >6% a month to hold it. (Steem is effectively charging >10X the rate speculators are willing to borrow at the majority of the time on Polo
https://poloniex.com/lending#BTC)
(This is also in contrast to the Synereo model which is sustainable because the incomes and rewards are sourced from advertising revenue.)