One of the underlying principles of free markets is the "Prisoner's Dilemma" which has been a battle cry for bitcoin maximalists who were astutely correct in realizing that none of the hundreds of bitcoin clones would surpass bitcoin's market cap. In a nutshell, it is an explanation of the free market principle that a new business must differentiate itself if it hopes to take market share from existing businesses in a particular sector. Here is a more detailed explanation.
https://bitcointalk.org/index.php?topic=1398586.0
Now, apply this same principle to STEEM, and you will see that STEEM has created a Prisoner's Dilemma for it's competitors who now have to differentiate themselves from STEEM if they hope to obtain market share in the "protected free speech blogging game".
The race to build a blockchain powered (immutable) Facebook is still wide open, however, and it appears that the 2 frontrunners are Synereo and Steemit. Keep a close eye on this race, because as soon as a minimum viable product is launched, that company will hit a billion dollar market cap easily.