Thanks for raising this. I think it's important we understand this. What is the value of steem? Facebook paid $1B for less than 100 million users. [1] Was that its value? Yes, because somebody paid for it. Thanks to trading markets, steem value should converge asymptotically to its actual value.
Granted the users with most steem power will heavily influence the curation, but this should evolve as more users use the application. Also, early steem adopters are very crypto-world oriented and they will heavily influence that, but what about more niche topics? Maybe I'm too optimistic but I think it will eventually converge to something interesting, useful and trustworthy.
[1] https://www.quora.com/How-many-users-does-Instagram-have